Better handling of issues during python setup

Fixes #1151
Merge remote-tracking branch 'upstream/master'

Conflicts:
	autoload/youcompleteme.vim
Updating to latest ycmd
Updating docs with correct defaults for option

Fixes #1156
Updating vimdoc from README
Merge remote-tracking branch 'upstream/master'

Conflicts:
	third_party/ycmd
Update submodule ycmd 88b30cc...b31611e

* ycmd 88b30cc...b31611e (1):
  > No default for ft=vim in DEFAULT_FILETYPE_TRIGGERS