Fix flake8 error/warning checking

Error/warning checking did not correctly parse output from flake8. This
resulted in Syntastic incorrectly displaying some warnings as errors.
Merge remote-tracking branch 'scrooloose/master'
use mix for elixir
Add highlight groups for the signs and the lines.

This allows users to customize the coloring of Syntastic's signs, and
also provides them a way to highlight the entire line using :sign's
linehl feature.  It preserves the current default behavior of using
the error and todo highlight groups if the customized ones aren't
present.  If the linehl group doesn't exist, then it's the same as not
specifying one, so no special highlighting for the line will occur.
always return list
Merge pull request #1 from xandox/use_mix_for_elixir

Use mix for elixir
remove unused function (because of 2519d83)
New checker for TeX / LaTeX: ChkTeX.
Typo: Check for puppet-lint, not puppet
Merge pull request #547 from docwhat/puppet-lint

Typo: Check for puppet-lint, not puppet
Fix syntax highlighting.

The variable force_highlight_callback is gone.

Highlight functions are now consistently named
SyntaxCheckers_<filetype>_<checker>_GetHighlightRegex(), and they
take precedence over highlighting based on column.
Merge pull request #540 from lcd047/chktex

New checker for TeX / LaTeX: ChkTeX.
Merge pull request #538 from joshuarh/simplify-ruby-checker

remove unused function (because of 2519d83)
Merge pull request #534 from xandox/master

Use mix for elixir if it available and vim started from project root
fix syntastic_auto_jump functionality

Previously we removed the code to automatically set the loclist and only
set it when required. This was needed because otherwise we could
interfere with other plugins that use the loclist.

Add the call to setloclist back in only if syntastic_auto_jump is set.
This will blow away the loclist every time the file is checked, but
setting syntastic_auto_jump is the users choice.

Fixes #533
Merge pull request #528 from jszakmeister/add-highlight-groups

Add highlight groups for the signs and the lines.
Merge pull request #465 from chazlever/master

Fix Flake8 Error/Warning Parsing
Made SyntacticIsVersionAtLeast more robust

It now handles more cases, which will cause Syntastic to degrade better
when commands return weird versions (e.g. the command crashes).