make magit-item-highlight not bold

The default value of `magit-item-highlight' had to be changed to make
use of the :bold instead of the :background face attribute so that it
does not override the `magit-diff-*' faces when using the default
theme.

This reverts this for zenburn.
Merge pull request #114 from tarsius/master

make magit-item-highlight not bold
added gitignore
get rid of eval local variables
adjusted zenburn colors and added some new
get rid of boxes and fringe
adjust some fontlock faces: warning, constant
added ediff mode
tweaked latex faces
tweaked org faces and outline weight
get rid of some explicit colors
tweaks to mu4e faces
adjust some low color fallbacks