Ensure uniqueness of PBXBuildFile object IDs.  Formerly, there would be collisions when two PBXBuildFiles referred to different PBXFileReferences identifying files with the same name in different directories, or when two PBXBuildFiles referred to different PBXReferenceProxies identifying target products with the same name in different remote project files.  It should now be impossible for PBXBuildFile IDs to collide unless the same file is added to the same build phase more than once - this should be considered illegal anyway.
Ensure uniqueness of PBXBuildFile object IDs.  Formerly, there would be
collisions when two PBXBuildFiles referred to different PBXFileReferences
identifying files with the same name in different directories, or when two
PBXBuildFiles referred to different PBXReferenceProxies identifying target
products with the same name in different remote project files.  It should
now be impossible for PBXBuildFile IDs to collide unless the same file is
added to the same build phase more than once - this should be considered
illegal anyway.


git-svn-id: e7e1075985beda50ea81ac4472467b4f6e91fc78@209 78cadc50-ecff-11dd-a971-7dbc132099af

clar/gyp,yinquan529/platform-external-chromium_org-tools-gyp,amoikevin/gyp,sport-monkey/GYP,IllusionRom-deprecated/android_platform_external_chromium_org_tools_gyp,trafi/gyp,kevinchen3315/gyp-git,erikge/watch_gyp,springmeyer/gyp,Phuehvk/gyp,saghul/gyn,azunite/gyp_20150930,LazyCodingCat/gyp,channing/gyp,AOSPU/external_chromium_org_tools_gyp,pandaxcl/gyp,Omegaphora/external_chromium_org_tools_gyp,yinquan529/platform-external-chromium_org-tools-gyp,bpsinc-native/src_tools_gyp,bulldy80/gyp_unofficial,brson/gyp,mapbox/gyp,sfiera/gyp,mgamer/gyp,ttyangf/pdfium_gyp,svn2github/gyp,azunite/gyp_20150930,okwasi/gyp,turbulenz/gyp,Omegaphora/external_chromium_org_tools_gyp,chromium/gyp,luvit/gyp,sport-monkey/GYP,AWhetter/gyp,LazyCodingCat/gyp,lukeweber/gyp-override,geekboxzone/lollipop_external_chromium_org_tools_gyp,mistydemeo/gyp,dougbeal/gyp,mkrautz/gyp-libmumble,okwasi/gyp,tarc/gyp,yjhjstz/gyp,svn2github/gyp,mkrautz/gyp-libmumble,erikge/watch_gyp,bulldy80/gyp_unofficial,ttyangf/gyp,xin3liang/platform_external_chromium_org_tools_gyp,carlTLR/gyp,Omegaphora/external_chromium_org_tools_gyp,openpeer/webrtc-gyp,carlTLR/gyp,sdklite/gyp,ttyangf/gyp,ttyangf/pdfium_gyp,dougbeal/gyp,sdklite/gyp,AOSPU/external_chromium_org_tools_gyp,ttyangf/gyp,clar/gyp,azunite/gyp,sdklite/gyp,azunite/gyp_20150930,tarc/gyp,ryfx/gyp,cysp/gyp,okumura/gyp,sanyaade-teachings/gyp,MIPS/external-chromium_org-tools-gyp,duanhjlt/gyp,trafi/gyp,sanyaade-teachings/gyp,carlTLR/gyp,tarc/gyp,springmeyer/gyp,azunite/gyp_20150930,ttyangf/pdfium_gyp,enkripsi/gyp,pandaxcl/gyp,lianliuwei/gyp,omasanori/gyp,luvit/gyp,lukeweber/gyp-override,Danath/gyp,mgamer/gyp,bnoordhuis/gyp,android-ia/platform_external_chromium_org_tools_gyp,alexcrichton/gyp,saghul/gyn,bnoordhuis/gyp,chromium/gyp,bnoordhuis/gyp,alexcrichton/gyp,svn2github/gyp,cchamberlain/gyp,lianliuwei/gyp,adblockplus/gyp,mumble-voip/libmumble-gyp,turbulenz/gyp,openpeer/webrtc-gyp,sanyaade-teachings/gyp,bdarnell/gyp,sdklite/gyp,bpsinc-native/src_tools_gyp,okumura/gyp,Jack-Q/GYP-copy,turbulenz/gyp,mapbox/gyp,mistydemeo/gyp,sport-monkey/GYP,Danath/gyp,luvit/gyp,bnq4ever/gypgoogle,geekboxzone/lollipop_external_chromium_org_tools_gyp,duanhjlt/gyp,ttyangf/pdfium_gyp,alexcrichton/gyp,IllusionRom-deprecated/android_platform_external_chromium_org_tools_gyp,ttyangf/gyp,bpsinc-native/src_tools_gyp,yangrongwei/gyp,ttyangf/pdfium_gyp,ryfx/gyp,bnoordhuis/gyp,svn2github/kgyp,Phuehvk/gyp,lianliuwei/gyp,azunite/gyp_20150930,yinquan529/platform-external-chromium_org-tools-gyp,sport-monkey/GYP,bpsinc-native/src_tools_gyp,MIPS/external-chromium_org-tools-gyp,sloanyang/gyp,MIPS/external-chromium_org-tools-gyp,enkripsi/gyp,sloanyang/gyp,mgamer/gyp,IllusionRom-deprecated/android_platform_external_chromium_org_tools_gyp,luvit/gyp,Chilledheart/gyp,saghul/gyn,xin3liang/platform_external_chromium_org_tools_gyp,springmeyer/gyp,channing/gyp,omasanori/gyp,Chilledheart/gyp,sdklite/gyp,bdarnell/gyp,android-ia/platform_external_chromium_org_tools_gyp,AOSPU/external_chromium_org_tools_gyp,brson/gyp,Phuehvk/gyp,mapbox/gyp,dougbeal/gyp,trafi/gyp,bulldy80/gyp_unofficial,pyokagan/gyp,pandaxcl/gyp,amoikevin/gyp,chromium/gyp,yangrongwei/gyp,erikge/watch_gyp,pyokagan/gyp,yjhjstz/gyp,xin3liang/platform_external_chromium_org_tools_gyp,kevinchen3315/gyp-git,android-ia/platform_external_chromium_org_tools_gyp,adblockplus/gyp,cysp/gyp,springmeyer/gyp,duanhjlt/gyp,AWhetter/gyp,sfiera/gyp,carlTLR/gyp,erikge/watch_gyp,carlTLR/gyp,bulldy80/gyp_unofficial,springmeyer/gyp,msc-/gyp,enkripsi/gyp,saghul/gyn,Phuehvk/gyp,Jack-Q/GYP-copy,clar/gyp,azunite/gyp,clar/gyp,lukeweber/gyp-override,AOSPU/external_chromium_org_tools_gyp,omasanori/gyp,bnq4ever/gypgoogle,sloanyang/gyp,trafi/gyp,Jack-Q/GYP-copy,bdarnell/gyp,turbulenz/gyp,omasanori/gyp,cchamberlain/gyp,AWhetter/gyp,okwasi/gyp,alexcrichton/gyp,tarc/gyp,okwasi/gyp,msc-/gyp,cchamberlain/gyp,IllusionRom-deprecated/android_platform_external_chromium_org_tools_gyp,mistydemeo/gyp,geekboxzone/lollipop_external_chromium_org_tools_gyp,svn2github/kgyp,xin3liang/platform_external_chromium_org_tools_gyp,lianliuwei/gyp,yjhjstz/gyp,brson/gyp,cysp/gyp,bnq4ever/gypgoogle,Chilledheart/gyp,kevinchen3315/gyp-git,mkrautz/gyp-libmumble,Danath/gyp,svn2github/kgyp,okumura/gyp,bulldy80/gyp_unofficial,ttyangf/gyp,pandaxcl/gyp,amoikevin/gyp,yjhjstz/gyp,Chilledheart/gyp,svn2github/kgyp,azunite/gyp,LazyCodingCat/gyp,mapbox/gyp,mumble-voip/libmumble-gyp,ryfx/gyp,mistydemeo/gyp,Omegaphora/external_chromium_org_tools_gyp,sloanyang/gyp,lukeweber/gyp-override,erikge/watch_gyp,pyokagan/gyp,mgamer/gyp,mgamer/gyp,yinquan529/platform-external-chromium_org-tools-gyp,openpeer/webrtc-gyp,yjhjstz/gyp,channing/gyp,enkripsi/gyp,sanyaade-teachings/gyp,Jack-Q/GYP-copy,MIPS/external-chromium_org-tools-gyp,svn2github/kgyp,bdarnell/gyp,bnq4ever/gypgoogle,duanhjlt/gyp,tarc/gyp,okumura/gyp,pyokagan/gyp,Chilledheart/gyp,clar/gyp,Danath/gyp,mumble-voip/libmumble-gyp,AWhetter/gyp,dougbeal/gyp,turbulenz/gyp,yangrongwei/gyp,pyokagan/gyp,pandaxcl/gyp,ryfx/gyp,kevinchen3315/gyp-git,bnq4ever/gypgoogle,cchamberlain/gyp,cchamberlain/gyp,LazyCodingCat/gyp,brson/gyp,openpeer/webrtc-gyp,sanyaade-teachings/gyp,Jack-Q/GYP-copy,azunite/gyp,sport-monkey/GYP,openpeer/webrtc-gyp,amoikevin/gyp,LazyCodingCat/gyp,Phuehvk/gyp,dougbeal/gyp,geekboxzone/lollipop_external_chromium_org_tools_gyp,channing/gyp,cysp/gyp,mumble-voip/libmumble-gyp,Danath/gyp,AWhetter/gyp,msc-/gyp,bnoordhuis/gyp,chromium/gyp,sfiera/gyp,saghul/gyn,android-ia/platform_external_chromium_org_tools_gyp,trafi/gyp,yangrongwei/gyp,ryfx/gyp,svn2github/gyp,mkrautz/gyp-libmumble,msc-/gyp,adblockplus/gyp,cysp/gyp,chromium/gyp,adblockplus/gyp,amoikevin/gyp,adblockplus/gyp,svn2github/gyp,msc-/gyp,mapbox/gyp,azunite/gyp,enkripsi/gyp,duanhjlt/gyp