Fix NeoBundle autoinstall settings

Check for actual installation instead of just the existence of the
NeoBundle directory.
Minor edit: Prettify section labels
Rearrange lines to avoid clobbering CDPATH

Source Antigen and Oh-My-Zsh first, since the latter sets a CDPATH
Minor edit: rearrange comments + clarify
Add 'norelativenumber' setting
Minor edit: 'enable syntax' before 'syntax sync'
Make autoresizing a setting instead of a function
Make last column highlighting smarter

Instead of fixing to a specific width, make it equal to
'textwidth' if possible.
Minor edit: put listchars on one line
Fix gui fonts

Use different settings for Unix GVim than for the others
Have SplitHere use local vars & no abbreviations
Set config editing maps to default to dotfiles
Map <Leader>sl to exec current line or selection

Cursor now stays in its starting position.
Make <num>~ actually delete the buffer
Make K more portable

Get rid of v:hlsearch dependency.
Minor edit: Expand 'exe' abbreviation
Add 'Rand' -- pRNG that uses /dev/urandom

Accepts a number 1-4 signifying bytesize of number; defaults to 3.
Remove git aliases already in Oh-My-Zsh

Repetitive redundancy is redundantly repetitive.
Make (GNU+BSD) 'ls' display with colors by default
Change 'fc -l 1' to alias from 'history' to 'hist'

Aliasing over a built-in command is rarely a wise idea.