User color scheme selection

Commit #120226

Users can now pick color schemes. I'll update this with some info later.
 
  Changes:
    + Color schemes are now in 'color_schemes' table
    + Instead of every theme having one scheme stored, all schemes are stored for user selection.
    + Scheme file information stored in 'extra_attr' column
    + In preparation for user custom schemes, the 'scheme' column will attempt to match with the 'name' column of a pre-made theme. If no match, in the future will assume it is a custom user theme. (Generate graphics/stylesheet)
    + Users can now pick color schemes for themes on a user basis via user/{uid}/edit. (YES)
   
  Known Quirks:
   - Color schemes are installed when color.module is installed.
   - New individual color themes are added when you go to admin/build/themes/settings/{theme}
   - When schemes are first installed, esp. after the module installation w/ a few color themes, the set messages list is very long. Need to find a way to quiet that.