Remove highlighting of columns 80+

Previously, characters in columns greater than 79 would have a
different background color to mark them as incompliant with PEP8.
However, I've found the feature moderately annoying -- especially
for writing or developing in languages other than Python. Thus,
for the time being, the feature has been removed.
Remove terminal timeout when exiting insert mode.

vim-powerline would have a small terminal timeout when Escape was
pressed to exit insert mode.
https://powerline.readthedocs.org/en/latest/tipstricks.html#fix-terminal-timeout-when-pressing-escape
discusses a method for removing this annoying delay.