[vim] Fixes broken augroup END command
Fixes $dotfiles dir setup for relative symlinks
Fixes completion stuff for Bash post-4.0
Removes redundant lines (already in driver.bash)
Removes hard-coded XTerm-specific up/down escapes

Instead use the standard terminfo codes via the `tput` command.  This
will work in non-XTerm terminal emulators.
Finishes sooner and noisier if dotfiles not found

No point in running a bunch of code if the dotfiles aren't set up such
that they can be found.
Sets up default TERM var if current not found

Mainly for my weird terminals (rxvt-unicode-24bit-super,
st-24bit-super), which don't have corresponding entries in terminfo
files.
Adds terminal-agnostic warn() function
[vim] Uses :autocmd instead of :auto consistently
(whitespace) [vim] Indents autocmds in an augroup
[vim] Improves filetype-specific autocmds

Uses :setlocal instead of :set.

Also handles BufNewFile event.

Combines multiple :set autocmds into single :setl autocmd.
(whitespace) [vim] Indents comments same as code