Adds a configuration option for whether the COLR atom and h.264 VUI header should...

Adds a configuration option for whether the COLR atom and h.264 VUI header should signal Bt.601 or Bt.7709 color, instead of just setting it based on whether the source is standard or high definition (which is preserved as default, and made more sensitive to letterboxed HD content).

git-svn-id: svn://localhost/HandBrake/trunk@1851 b64f7644-9d1e-0410-96f1-a4d463321fa5