lint-hunks: better support for working tree
lint-hunks: better support for working tree

When run with no arguments, report warnings in the diff between the
working tree and HEAD. With arguments, report warnings in the diff
between the named commit and its parents.

Change-Id: Ie10dcdecb303edf8af51bad645cc11206a1fc26b

abwiz0086/webm.libvpx,pcwalton/libvpx,stewnorriss/libvpx,GrokImageCompression/aom,kalli123/webm.libvpx,WebRTC-Labs/libvpx,felipebetancur/libvpx,GrokImageCompression/aom,charup/https---github.com-webmproject-libvpx-,hsueceumd/test_hui,ittiamvpx/libvpx,webmproject/libvpx,shyamalschandra/libvpx,smarter/aom,mwgoldsmith/libvpx,VTCSecureLLC/libvpx,felipebetancur/libvpx,mwgoldsmith/libvpx,pcwalton/libvpx,zofuthan/libvpx,ittiamvpx/libvpx,luctrudeau/aom,cinema6/libvpx,hsueceumd/test_hui,n4t/libvpx,iniwf/webm.libvpx,reimaginemedia/webm.libvpx,jacklicn/webm.libvpx,felipebetancur/libvpx,jdm/libvpx,running770/libvpx,reimaginemedia/webm.libvpx,kim42083/webm.libvpx,mwgoldsmith/libvpx,shareefalis/libvpx,pcwalton/libvpx,VTCSecureLLC/libvpx,mbebenita/aom,luctrudeau/aom,iniwf/webm.libvpx,altogother/webm.libvpx,jmvalin/aom,cinema6/libvpx,gshORTON/webm.libvpx,zofuthan/libvpx,gshORTON/webm.libvpx,VTCSecureLLC/libvpx,openpeer/libvpx_new,GrokImageCompression/aom,turbulenz/libvpx,openpeer/libvpx_new,cinema6/libvpx,thdav/aom,goodleixiao/vpx,turbulenz/libvpx,Distrotech/libvpx,turbulenz/libvpx,luctrudeau/aom,altogother/webm.libvpx,abwiz0086/webm.libvpx,VTCSecureLLC/libvpx,ittiamvpx/libvpx-1,goodleixiao/vpx,n4t/libvpx,kim42083/webm.libvpx,reimaginemedia/webm.libvpx,ShiftMediaProject/libvpx,running770/libvpx,shyamalschandra/libvpx,matanbs/webm.libvpx,mbebenita/aom,Topopiccione/libvpx,gshORTON/webm.libvpx,vasilvv/esvp8,mwgoldsmith/vpx,kleopatra999/webm.libvpx,matanbs/vp982,gshORTON/webm.libvpx,Laknot/libvpx,lyx2014/libvpx_c,zofuthan/libvpx,matanbs/webm.libvpx,kalli123/webm.libvpx,goodleixiao/vpx,hsueceumd/test_hui,mbebenita/aom,lyx2014/libvpx_c,turbulenz/libvpx,stewnorriss/libvpx,thdav/aom,gshORTON/webm.libvpx,jacklicn/webm.libvpx,ShiftMediaProject/libvpx,altogother/webm.libvpx,shyamalschandra/libvpx,felipebetancur/libvpx,vasilvv/esvp8,liqianggao/libvpx,kleopatra999/webm.libvpx,Maria1099/webm.libvpx,webmproject/libvpx,cinema6/libvpx,altogother/webm.libvpx,kleopatra999/webm.libvpx,lyx2014/libvpx_c,stewnorriss/libvpx,Laknot/libvpx,Topopiccione/libvpx,Distrotech/libvpx,vasilvv/esvp8,mwgoldsmith/vpx,Distrotech/libvpx,liqianggao/libvpx,matanbs/vp982,webmproject/libvpx,mwgoldsmith/vpx,felipebetancur/libvpx,altogother/webm.libvpx,kleopatra999/webm.libvpx,iniwf/webm.libvpx,WebRTC-Labs/libvpx,iniwf/webm.libvpx,mbebenita/aom,shyamalschandra/libvpx,jmvalin/aom,cinema6/libvpx,shyamalschandra/libvpx,jmvalin/aom,pcwalton/libvpx,abwiz0086/webm.libvpx,n4t/libvpx,smarter/aom,goodleixiao/vpx,luctrudeau/aom,webmproject/libvpx,Laknot/libvpx,GrokImageCompression/aom,cinema6/libvpx,Laknot/libvpx,Acidburn0zzz/webm.libvpx,Suvarna1488/webm.libvpx,Maria1099/webm.libvpx,charup/https---github.com-webmproject-libvpx-,zofuthan/libvpx,stewnorriss/libvpx,Acidburn0zzz/webm.libvpx,kim42083/webm.libvpx,Maria1099/webm.libvpx,liqianggao/libvpx,n4t/libvpx,vasilvv/esvp8,charup/https---github.com-webmproject-libvpx-,Acidburn0zzz/webm.libvpx,turbulenz/libvpx,vasilvv/esvp8,reimaginemedia/webm.libvpx,matanbs/vp982,ShiftMediaProject/libvpx,gshORTON/webm.libvpx,Topopiccione/libvpx,pcwalton/libvpx,n4t/libvpx,Acidburn0zzz/webm.libvpx,kleopatra999/webm.libvpx,liqianggao/libvpx,shareefalis/libvpx,lyx2014/libvpx_c,sanyaade-teachings/libvpx,sanyaade-teachings/libvpx,shacklettbp/aom,running770/libvpx,jdm/libvpx,iniwf/webm.libvpx,ittiamvpx/libvpx,ittiamvpx/libvpx-1,lyx2014/libvpx_c,Suvarna1488/webm.libvpx,mwgoldsmith/vpx,jdm/libvpx,jmvalin/aom,ittiamvpx/libvpx-1,Suvarna1488/webm.libvpx,mwgoldsmith/vpx,mbebenita/aom,openpeer/libvpx_new,turbulenz/libvpx,vasilvv/esvp8,webmproject/libvpx,VTCSecureLLC/libvpx,mbebenita/aom,GrokImageCompression/aom,felipebetancur/libvpx,stewnorriss/libvpx,zofuthan/libvpx,GrokImageCompression/aom,Suvarna1488/webm.libvpx,jacklicn/webm.libvpx,goodleixiao/vpx,shacklettbp/aom,jdm/libvpx,kleopatra999/webm.libvpx,jacklicn/webm.libvpx,Topopiccione/libvpx,mwgoldsmith/libvpx,shacklettbp/aom,smarter/aom,goodleixiao/vpx,kim42083/webm.libvpx,ittiamvpx/libvpx-1,openpeer/libvpx_new,mbebenita/aom,thdav/aom,openpeer/libvpx_new,stewnorriss/libvpx,sanyaade-teachings/libvpx,VTCSecureLLC/libvpx,turbulenz/libvpx,charup/https---github.com-webmproject-libvpx-,smarter/aom,shacklettbp/aom,Maria1099/webm.libvpx,liqianggao/libvpx,shareefalis/libvpx,matanbs/vp982,Topopiccione/libvpx,thdav/aom,matanbs/webm.libvpx,shacklettbp/aom,kim42083/webm.libvpx,Suvarna1488/webm.libvpx,smarter/aom,WebRTC-Labs/libvpx,ittiamvpx/libvpx-1,vasilvv/esvp8,shareefalis/libvpx,Suvarna1488/webm.libvpx,jdm/libvpx,smarter/aom,Acidburn0zzz/webm.libvpx,openpeer/libvpx_new,Distrotech/libvpx,luctrudeau/aom,reimaginemedia/webm.libvpx,mbebenita/aom,cinema6/libvpx,charup/https---github.com-webmproject-libvpx-,jdm/libvpx,shareefalis/libvpx,ShiftMediaProject/libvpx,ittiamvpx/libvpx,ittiamvpx/libvpx-1,kim42083/webm.libvpx,shyamalschandra/libvpx,webmproject/libvpx,reimaginemedia/webm.libvpx,kalli123/webm.libvpx,abwiz0086/webm.libvpx,shareefalis/libvpx,matanbs/webm.libvpx,matanbs/vp982,luctrudeau/aom,Maria1099/webm.libvpx,hsueceumd/test_hui,jmvalin/aom,matanbs/webm.libvpx,shacklettbp/aom,Laknot/libvpx,zofuthan/libvpx,charup/https---github.com-webmproject-libvpx-,mwgoldsmith/libvpx,thdav/aom,Distrotech/libvpx,WebRTC-Labs/libvpx,jacklicn/webm.libvpx,mwgoldsmith/vpx,Maria1099/webm.libvpx,mwgoldsmith/libvpx,abwiz0086/webm.libvpx,Topopiccione/libvpx,lyx2014/libvpx_c,running770/libvpx,running770/libvpx,kalli123/webm.libvpx,jacklicn/webm.libvpx,Laknot/libvpx,iniwf/webm.libvpx,sanyaade-teachings/libvpx,Acidburn0zzz/webm.libvpx,thdav/aom,kalli123/webm.libvpx,ittiamvpx/libvpx,sanyaade-teachings/libvpx,hsueceumd/test_hui,ShiftMediaProject/libvpx,Distrotech/libvpx,jmvalin/aom,running770/libvpx,mbebenita/aom,liqianggao/libvpx,turbulenz/libvpx,WebRTC-Labs/libvpx,hsueceumd/test_hui,turbulenz/libvpx,matanbs/vp982,matanbs/webm.libvpx,abwiz0086/webm.libvpx,kalli123/webm.libvpx,pcwalton/libvpx,matanbs/vp982,altogother/webm.libvpx,ittiamvpx/libvpx