Make sure that diff is splitting vertically.

This is here to make :Gdiff from fugitive work nicer.
Map <F2> to tie scrolling of windows together.

There was some bugginess with the autocammands that needed fixig.
Change map to nnoremap because ??
Have the Colors for MiniBuf not be wiped
Prefixing vars with Ulf to avoid namingconflicts.

Also changing comment-vars from script-variables to buffer-variables to
get correct commenting when multiple files are loaded.
Change the default list of colorschemes to cycle

The list of colorschemes to cycle through with <F4>.