Allow variables with magic suffixes (_files, et al.) to be excludable and matchable with 'sources!/'.
Allow variables with magic suffixes (_files, et al.) to be excludable and matchable with 'sources!/'.

R=mark
BUG=16395
TEST=projects are still generated correctly for all platforms.

Review URL: http://codereview.chromium.org/155438

git-svn-id: e7e1075985beda50ea81ac4472467b4f6e91fc78@547 78cadc50-ecff-11dd-a971-7dbc132099af

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