fix g:solarized_termtrans

Change s:base02 to "0" for g:solarized_termtrans = 1.
fix bold-italic
No background color to highlight SpecialKey

This avoids having dark background for these chars when in light mode.
added CursorLineNr, which seems to have been added to vim recently (first noticed in vim-X11-2:7.3.515-1.fc17.x86_64)
Fixing a formatting bug in Advance Configuration

The "pre-formated text" part in "Advance Configuration" section needed a blank line before it to display properly.
Link SignColumn to LineNr
Add highlight definitions for vim-gitgutter
Typo in README.mkd

Fixes very minor typo in README.mkd
Enable togglebg to be reloaded

This makes it easier to develop the plugin at the only cost of not
spewing an unhelpful error in the unlikely event some other plugin chose
the same <Plug> map.
Clean up maps in togglebg
Simplify togglebg#map()

Allow errors to bubble out of togglebg#map() (so the user knows, e.g.,
if they gave an invalid argument) and guard against clobbering an <F5>
map instead.  Also drop <unique> as a user can pass that in if desired.