add/change plugins
add more mappings
fix syntax error with commented quote
set more usability options

enable matchit, enable folding, set a scrolloff
move some GUI-specific settings to gvimrc; add color setting

Now the color scheme looks better in Terminal, since it’s wombat256 instead of wombat. But Vim in a GUI still looks as good.

Also added a color setting to fix one broken color, MatchParen.