index_add_all: remove conflicts when no wd file
index_add_all: remove conflicts when no wd file

If there exists a conflict in the index, but no file in the working
directory, this implies that the user wants to accept the resolution
by removing the file.  Thus, remove the conflict entry from the
index, instead of trying to add a (nonexistent) file.

mrksrm/Mingijura,t0xicCode/libgit2,skabel/manguse,since2014/libgit2,magnus98/TEST,leoyanggit/libgit2,since2014/libgit2,mcanthony/libgit2,yongthecoder/libgit2,dleehr/libgit2,stewid/libgit2,leoyanggit/libgit2,nokiddin/libgit2,iankronquist/libgit2,kissthink/libgit2,sygool/libgit2,Corillian/libgit2,mingyaaaa/libgit2,claudelee/libgit2,yosefhackmon/libgit2,spraints/libgit2,nokiddin/libgit2,t0xicCode/libgit2,leoyanggit/libgit2,joshtriplett/libgit2,t0xicCode/libgit2,yongthecoder/libgit2,dleehr/libgit2,spraints/libgit2,Tousiph/Demo1,MrHacky/libgit2,Corillian/libgit2,yosefhackmon/libgit2,falqas/libgit2,stewid/libgit2,skabel/manguse,mhp/libgit2,kissthink/libgit2,kenprice/libgit2,iankronquist/libgit2,skabel/manguse,MrHacky/libgit2,oaastest/libgit2,magnus98/TEST,jeffhostetler/public_libgit2,saurabhsuniljain/libgit2,KTXSoftware/libgit2,kenprice/libgit2,sim0629/libgit2,leoyanggit/libgit2,yosefhackmon/libgit2,sim0629/libgit2,joshtriplett/libgit2,leoyanggit/libgit2,ardumont/libgit2,yosefhackmon/libgit2,kissthink/libgit2,linquize/libgit2,oaastest/libgit2,amyvmiwei/libgit2,yongthecoder/libgit2,saurabhsuniljain/libgit2,iankronquist/libgit2,magnus98/TEST,mrksrm/Mingijura,Corillian/libgit2,jeffhostetler/public_libgit2,jeffhostetler/public_libgit2,MrHacky/libgit2,JIghtuse/libgit2,iankronquist/libgit2,KTXSoftware/libgit2,mcanthony/libgit2,ardumont/libgit2,Tousiph/Demo1,skabel/manguse,mingyaaaa/libgit2,since2014/libgit2,Tousiph/Demo1,linquize/libgit2,dleehr/libgit2,sygool/libgit2,mcanthony/libgit2,magnus98/TEST,KTXSoftware/libgit2,JIghtuse/libgit2,falqas/libgit2,JIghtuse/libgit2,kissthink/libgit2,falqas/libgit2,mcanthony/libgit2,linquize/libgit2,linquize/libgit2,falqas/libgit2,ardumont/libgit2,nokiddin/libgit2,MrHacky/libgit2,dleehr/libgit2,ardumont/libgit2,falqas/libgit2,t0xicCode/libgit2,spraints/libgit2,iankronquist/libgit2,stewid/libgit2,skabel/manguse,claudelee/libgit2,stewid/libgit2,kissthink/libgit2,joshtriplett/libgit2,kenprice/libgit2,Corillian/libgit2,claudelee/libgit2,Tousiph/Demo1,claudelee/libgit2,Corillian/libgit2,amyvmiwei/libgit2,ardumont/libgit2,since2014/libgit2,mingyaaaa/libgit2,since2014/libgit2,sim0629/libgit2,mcanthony/libgit2,iankronquist/libgit2,stewid/libgit2,nokiddin/libgit2,mhp/libgit2,claudelee/libgit2,oaastest/libgit2,kenprice/libgit2,spraints/libgit2,t0xicCode/libgit2,spraints/libgit2,kenprice/libgit2,KTXSoftware/libgit2,JIghtuse/libgit2,oaastest/libgit2,MrHacky/libgit2,linquize/libgit2,joshtriplett/libgit2,saurabhsuniljain/libgit2,joshtriplett/libgit2,mhp/libgit2,sygool/libgit2,nokiddin/libgit2,yongthecoder/libgit2,linquize/libgit2,dleehr/libgit2,stewid/libgit2,mhp/libgit2,nokiddin/libgit2,sim0629/libgit2,ardumont/libgit2,skabel/manguse,mrksrm/Mingijura,JIghtuse/libgit2,spraints/libgit2,saurabhsuniljain/libgit2,jeffhostetler/public_libgit2,KTXSoftware/libgit2,saurabhsuniljain/libgit2,sygool/libgit2,mhp/libgit2,amyvmiwei/libgit2,jeffhostetler/public_libgit2,kenprice/libgit2,leoyanggit/libgit2,mingyaaaa/libgit2,magnus98/TEST,t0xicCode/libgit2,saurabhsuniljain/libgit2,oaastest/libgit2,mcanthony/libgit2,oaastest/libgit2,since2014/libgit2,mrksrm/Mingijura,amyvmiwei/libgit2,claudelee/libgit2,Corillian/libgit2,MrHacky/libgit2,kissthink/libgit2,sygool/libgit2,mrksrm/Mingijura,Tousiph/Demo1,sim0629/libgit2,yosefhackmon/libgit2,joshtriplett/libgit2,sim0629/libgit2,yongthecoder/libgit2,magnus98/TEST,jeffhostetler/public_libgit2,Tousiph/Demo1,yongthecoder/libgit2,mingyaaaa/libgit2,dleehr/libgit2,JIghtuse/libgit2,mrksrm/Mingijura,KTXSoftware/libgit2,sygool/libgit2,amyvmiwei/libgit2,mhp/libgit2,mingyaaaa/libgit2,yosefhackmon/libgit2,amyvmiwei/libgit2,falqas/libgit2