ENH: Add a version for the FreeSurferColorLUT_YYYMMDD.txt so that multiple versions can be available.

The first line of the FreeSurferColorLUT.txt file as provided from the freesurfer binary distributions contains a source code date-time stamp
that can be used to version the files unabiguously.
ENH: Add stock un-altered version of the LUT for 20120827 directly form freesurfer

The next patch set will modify this file for slicers purposes.
ENH: Modify for Slicer LUT conformance

s/^#/# /g  <-- Comment lines need a space after the #
s/0$/255/g <-- the alpha channel needs to be 255 in all cases except unknown
%s/\(nknown.* \)255$/\1 0/g   <-- unknowns need to be transparent
ENH: Change Default LUT to the 2012 freesurfer version.