Don't copy css files into doc/html.

[SVN r64180]

doc/Jamfile.v2

@@ -81,8 +81,6 @@ boostbook doc
     <dependency>callouts
     ;
 
-install css : [ glob src/*.css ] : <location>html ;
-explicit css ;
 install images : [ glob src/images/*.png ] : <location>html/images ;
 explicit images ;
 install callouts : [ glob src/images/callouts/*.png ] : <location>html/images/callouts ;