Erlang: correctly handle additional LibDirs

The compile function expects a list of paths in the LibDirs parameter,
however when calling erlang_check_file.erl with an additional path (for
example when using the "g:syntastic_erlc_include_path" option), a
string would be passed instead. Because strings in Erlang are lists,
each character of the string would have been interpreted as a lib path.
Merge pull request #1182 from russss/master

Erlang: correctly handle additional LibDirs
Make `b:syntastic_skip_checks` suitable for general use.

Document `b:syntastic_skip_checks`.  Minor cleanup.
SASS checker: fix errorformat.
enable warnings for eruby files
Merge pull request #1187 from rradonic/enable-warnings

eRuby checker: enable warnings.  Adjust errorformat accordingly.
Bug fix: grouping in errorformat.

\(...\) can't be used in errorformat; use non-catching \%(...\) instead.
Add \m to patterns that use grouping.
Pylint checker: more versioning delirium.
working on pc_lint checker
README: add a note about style checkers.  Minor cleanup.
Grammar.
- pc_lint seems to be working well now.
Merge remote-tracking branch '2sb18/pc_lint'
PC-Lint: cleanup.
Add support for maven customizations