Add __standalone_mode__ variable to differentiate between build modes
Add __standalone_mode__ variable to differentiate between build modes

In some cases plugins needs to differentiate the path of dependencies
in gerrit tree and standalone build mode. Provide python variable and
set it to True and False in standalone and in gerrit tree modes.

Change-Id: I437f2c883ed7c0f335896567b5470d15b34512a4

thesamet/gerrit,hdost/gerrit,netroby/gerrit,dwhipstock/gerrit,WANdisco/gerrit,thesamet/gerrit,Distrotech/gerrit,thesamet/gerrit,TonyChai24/test,thesamet/gerrit,GerritCodeReview/gerrit,supriyantomaftuh/gerrit,GerritCodeReview/gerrit,dwhipstock/gerrit,hdost/gerrit,WANdisco/gerrit,netroby/gerrit,pkdevbox/gerrit,gerrit-review/gerrit,anminhsu/gerrit,qtproject/qtqa-gerrit,anminhsu/gerrit,GerritCodeReview/gerrit,TonyChai24/test,hdost/gerrit,jackminicloud/test,thesamet/gerrit,WANdisco/gerrit,thinkernel/gerrit,Distrotech/gerrit,WANdisco/gerrit,thinkernel/gerrit,qtproject/qtqa-gerrit,renchaorevee/gerrit,thinkernel/gerrit,thinkernel/gerrit,anminhsu/gerrit,hdost/gerrit,quyixia/gerrit,joshuawilson/merrit,hdost/gerrit,hdost/gerrit,supriyantomaftuh/gerrit,Seinlin/gerrit,Overruler/gerrit,Overruler/gerrit,Seinlin/gerrit,anminhsu/gerrit,gerrit-review/gerrit,thinkernel/gerrit,quyixia/gerrit,pkdevbox/gerrit,jackminicloud/test,dwhipstock/gerrit,gcoders/gerrit,GerritCodeReview/gerrit,joshuawilson/merrit,gerrit-review/gerrit,jackminicloud/test,Overruler/gerrit,netroby/gerrit,quyixia/gerrit,MerritCR/merrit,Distrotech/gerrit,gerrit-review/gerrit,pkdevbox/gerrit,dwhipstock/gerrit,Seinlin/gerrit,TonyChai24/test,pkdevbox/gerrit,thinkernel/gerrit,netroby/gerrit,gcoders/gerrit,Distrotech/gerrit,MerritCR/merrit,supriyantomaftuh/gerrit,Overruler/gerrit,MerritCR/merrit,TonyChai24/test,dwhipstock/gerrit,TonyChai24/test,quyixia/gerrit,qtproject/qtqa-gerrit,renchaorevee/gerrit,pkdevbox/gerrit,renchaorevee/gerrit,thesamet/gerrit,MerritCR/merrit,Distrotech/gerrit,joshuawilson/merrit,GerritCodeReview/gerrit,TonyChai24/test,MerritCR/merrit,netroby/gerrit,qtproject/qtqa-gerrit,supriyantomaftuh/gerrit,Overruler/gerrit,anminhsu/gerrit,dwhipstock/gerrit,qtproject/qtqa-gerrit,Seinlin/gerrit,qtproject/qtqa-gerrit,jackminicloud/test,gerrit-review/gerrit,gcoders/gerrit,joshuawilson/merrit,dwhipstock/gerrit,supriyantomaftuh/gerrit,gcoders/gerrit,renchaorevee/gerrit,quyixia/gerrit,joshuawilson/merrit,anminhsu/gerrit,netroby/gerrit,pkdevbox/gerrit,jackminicloud/test,jackminicloud/test,Distrotech/gerrit,gcoders/gerrit,supriyantomaftuh/gerrit,GerritCodeReview/gerrit,jackminicloud/test,gerrit-review/gerrit,supriyantomaftuh/gerrit,hdost/gerrit,renchaorevee/gerrit,joshuawilson/merrit,netroby/gerrit,renchaorevee/gerrit,gcoders/gerrit,thinkernel/gerrit,gcoders/gerrit,Distrotech/gerrit,quyixia/gerrit,anminhsu/gerrit,MerritCR/merrit,qtproject/qtqa-gerrit,WANdisco/gerrit,Seinlin/gerrit,joshuawilson/merrit,gerrit-review/gerrit,pkdevbox/gerrit,MerritCR/merrit,Overruler/gerrit,MerritCR/merrit,WANdisco/gerrit,GerritCodeReview/gerrit,Seinlin/gerrit,joshuawilson/merrit,GerritCodeReview/gerrit,thesamet/gerrit,renchaorevee/gerrit,TonyChai24/test,quyixia/gerrit,WANdisco/gerrit,Seinlin/gerrit