Add version comparision functions

Add version comparision functions to the core menv functionality.
Altered the gitconfig to color ui

Altered the gitconfig to color ui
Change the git push.default for certain versions

Change the git push.default for certain versions that do not support it.
Only run gnome if it is installed on the system

Only run gnome if it is installed on the system. This also means it will
only be install if gnome is present. By present we mean gnome version >=
3.8.4 as we don't care about supporting things such as gconf.
Fixed a style error in the gnome code.

Fixed a style error in the gnome code.
Cleaned up history to work between menv sessions.

Cleaned up history to work between menv sessions.
Added my dirs stack for pushing and popping

Added my dirs stack for pushing and popping that is saved automatically.