base.bbclass: Add base_path_relative.
base.bbclass: Add base_path_relative.

base_path_relative returns a relative path from src to dest.

Examples:

>>> base_path_relative("/usr/bin", "/tmp/foo/bar")
../../tmp/foo/bar

>>> base_path_relative("/usr/bin", "/usr/lib")
../lib

>>> base_path_relative("/tmp", "/tmp/foo/bar")
foo/bar

Signed-off-by: Chris Larson <8cf06b7089d5169434d5def8b2d1c9c9c95f6e71@mvista.com>

nx111/openembeded_openpli2.1_nx111,sledz/oe,YtvwlD/od-oe,hulifox008/openembedded,dellysunnymtech/sakoman-oe,yyli/overo-oe,xifengchuo/openembedded,JamesAng/oe,SIFTeam/openembedded,openpli-arm/openembedded,SIFTeam/openembedded,dave-billin/overo-ui-moos-auv,John-NY/overo-oe,trini/openembedded,nlebedenco/mini2440,buglabs/oe-buglabs,nx111/openembeded_openpli2.1_nx111,troth/oe-ts7xxx,YtvwlD/od-oe,BlackPole/bp-openembedded,trini/openembedded,crystalfontz/openembedded,SIFTeam/openembedded,dellysunnymtech/sakoman-oe,xifengchuo/openembedded,John-NY/overo-oe,sampov2/audio-openembedded,nx111/openembeded_openpli2.1_nx111,scottellis/overo-oe,nlebedenco/mini2440,BlackPole/bp-openembedded,trini/openembedded,openembedded/openembedded,hulifox008/openembedded,openembedded/openembedded,JrCs/opendreambox,JamesAng/goe,sutajiokousagi/openembedded,popazerty/openembedded-cuberevo,bticino/openembedded,nvl1109/openembeded,libo/openembedded,demsey/openembedded,anguslees/openembedded-android,Martix/Eonos,SIFTeam/openembedded,John-NY/overo-oe,KDAB/OpenEmbedded-Archos,YtvwlD/od-oe,nx111/openembeded_openpli2.1_nx111,xifengchuo/openembedded,giobauermeister/openembedded,openembedded/openembedded,KDAB/OpenEmbedded-Archos,bticino/openembedded,JrCs/opendreambox,popazerty/openembedded-cuberevo,rascalmicro/openembedded-rascal,libo/openembedded,mrchapp/arago-oe-dev,troth/oe-ts7xxx,buglabs/oe-buglabs,philb/pbcl-oe-2010,sutajiokousagi/openembedded,KDAB/OpenEmbedded-Archos,nvl1109/openembeded,thebohemian/openembedded,crystalfontz/openembedded,trini/openembedded,troth/oe-ts7xxx,nx111/openembeded_openpli2.1_nx111,openpli-arm/openembedded,philb/pbcl-oe-2010,nvl1109/openembeded,sentient-energy/emsw-oe-mirror,sledz/oe,JamesAng/oe,crystalfontz/openembedded,xifengchuo/openembedded,giobauermeister/openembedded,xifengchuo/openembedded,nvl1109/openembeded,troth/oe-ts7xxx,philb/pbcl-oe-2010,sampov2/audio-openembedded,sampov2/audio-openembedded,SIFTeam/openembedded,demsey/openembedded,anguslees/openembedded-android,thebohemian/openembedded,thebohemian/openembedded,demsey/openembedded,sledz/oe,dave-billin/overo-ui-moos-auv,dellysunnymtech/sakoman-oe,openpli-arm/openembedded,dave-billin/overo-ui-moos-auv,KDAB/OpenEmbedded-Archos,dave-billin/overo-ui-moos-auv,dellysunnymtech/sakoman-oe,YtvwlD/od-oe,anguslees/openembedded-android,bticino/openembedded,sentient-energy/emsw-oe-mirror,philb/pbcl-oe-2010,giobauermeister/openembedded,thebohemian/openembedded,scottellis/overo-oe,xifengchuo/openembedded,BlackPole/bp-openembedded,buglabs/oe-buglabs,BlackPole/bp-openembedded,giobauermeister/openembedded,nzjrs/overo-openembedded,xifengchuo/openembedded,openpli-arm/openembedded,rascalmicro/openembedded-rascal,openembedded/openembedded,popazerty/openembedded-cuberevo,BlackPole/bp-openembedded,mrchapp/arago-oe-dev,BlackPole/bp-openembedded,buglabs/oe-buglabs,sutajiokousagi/openembedded,demsey/openenigma2,crystalfontz/openembedded,crystalfontz/openembedded,popazerty/openembedded-cuberevo,anguslees/openembedded-android,rascalmicro/openembedded-rascal,xifengchuo/openembedded,openpli-arm/openembedded,libo/openembedded,troth/oe-ts7xxx,JrCs/opendreambox,anguslees/openembedded-android,giobauermeister/openembedded,yyli/overo-oe,JamesAng/goe,hulifox008/openembedded,JrCs/opendreambox,yyli/overo-oe,JamesAng/goe,sentient-energy/emsw-oe-mirror,demsey/openenigma2,hulifox008/openembedded,JrCs/opendreambox,sutajiokousagi/openembedded,dave-billin/overo-ui-moos-auv,demsey/openembedded,nx111/openembeded_openpli2.1_nx111,thebohemian/openembedded,giobauermeister/openembedded,dellysunnymtech/sakoman-oe,openembedded/openembedded,libo/openembedded,hulifox008/openembedded,nlebedenco/mini2440,nvl1109/openembeded,sampov2/audio-openembedded,bticino/openembedded,scottellis/overo-oe,yyli/overo-oe,YtvwlD/od-oe,mrchapp/arago-oe-dev,openembedded/openembedded,philb/pbcl-oe-2010,rascalmicro/openembedded-rascal,JamesAng/goe,sutajiokousagi/openembedded,demsey/openenigma2,giobauermeister/openembedded,dave-billin/overo-ui-moos-auv,nvl1109/openembeded,scottellis/overo-oe,rascalmicro/openembedded-rascal,nlebedenco/mini2440,openembedded/openembedded,yyli/overo-oe,demsey/openenigma2,KDAB/OpenEmbedded-Archos,KDAB/OpenEmbedded-Archos,openembedded/openembedded,dellysunnymtech/sakoman-oe,popazerty/openembedded-cuberevo,buglabs/oe-buglabs,SIFTeam/openembedded,trini/openembedded,JamesAng/oe,nlebedenco/mini2440,yyli/overo-oe,crystalfontz/openembedded,nlebedenco/mini2440,yyli/overo-oe,sutajiokousagi/openembedded,giobauermeister/openembedded,troth/oe-ts7xxx,sentient-energy/emsw-oe-mirror,openpli-arm/openembedded,thebohemian/openembedded,troth/oe-ts7xxx,popazerty/openembedded-cuberevo,JamesAng/goe,nx111/openembeded_openpli2.1_nx111,John-NY/overo-oe,buglabs/oe-buglabs,trini/openembedded,JamesAng/goe,anguslees/openembedded-android,BlackPole/bp-openembedded,Martix/Eonos,scottellis/overo-oe,nx111/openembeded_openpli2.1_nx111,nzjrs/overo-openembedded,scottellis/overo-oe,dave-billin/overo-ui-moos-auv,rascalmicro/openembedded-rascal,sledz/oe,sentient-energy/emsw-oe-mirror,mrchapp/arago-oe-dev,nzjrs/overo-openembedded,JrCs/opendreambox,openembedded/openembedded,giobauermeister/openembedded,bticino/openembedded,JrCs/opendreambox,buglabs/oe-buglabs,yyli/overo-oe,scottellis/overo-oe,dellysunnymtech/sakoman-oe,nzjrs/overo-openembedded,demsey/openenigma2,sutajiokousagi/openembedded,bticino/openembedded,sentient-energy/emsw-oe-mirror,JamesAng/oe,JamesAng/oe,sentient-energy/emsw-oe-mirror,hulifox008/openembedded,sampov2/audio-openembedded,JamesAng/oe,philb/pbcl-oe-2010,dellysunnymtech/sakoman-oe,trini/openembedded,Martix/Eonos,YtvwlD/od-oe,nvl1109/openembeded,nlebedenco/mini2440,sledz/oe,John-NY/overo-oe,Martix/Eonos,mrchapp/arago-oe-dev,mrchapp/arago-oe-dev,thebohemian/openembedded,dellysunnymtech/sakoman-oe,hulifox008/openembedded,rascalmicro/openembedded-rascal,crystalfontz/openembedded,libo/openembedded,JamesAng/oe,popazerty/openembedded-cuberevo,anguslees/openembedded-android,John-NY/overo-oe,Martix/Eonos,demsey/openembedded,demsey/openenigma2,sampov2/audio-openembedded,JamesAng/goe,YtvwlD/od-oe,nzjrs/overo-openembedded,demsey/openembedded,demsey/openenigma2,SIFTeam/openembedded,sledz/oe,JrCs/opendreambox,libo/openembedded,John-NY/overo-oe,bticino/openembedded,libo/openembedded,philb/pbcl-oe-2010,KDAB/OpenEmbedded-Archos,sampov2/audio-openembedded,openembedded/openembedded,popazerty/openembedded-cuberevo,nzjrs/overo-openembedded,JrCs/opendreambox,openpli-arm/openembedded,buglabs/oe-buglabs,demsey/openembedded,rascalmicro/openembedded-rascal,Martix/Eonos,YtvwlD/od-oe,sledz/oe,openembedded/openembedded,Martix/Eonos,mrchapp/arago-oe-dev,nzjrs/overo-openembedded,xifengchuo/openembedded