The xsltproc command in the Makefile now uses the XSL Customization
layer style sheet poky-ref-manual-customization.xsl for the style
sheet parameter. This method will allow for customization of the
HTML version formatting that might be unique for the manual. I have
added the new file to the file structure.
Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>