Merge branch 'registry_cleanup'
Update docs to describe the new checker infrastructure.
Bump version number.
Fix luac highlighting.
Update errorformat for fsc and scalac.
Minor cleanup.
Javac: fix path munging under Cygwin.
Update: shallcheck no longer has a jsoncheck.
Detailed debugging.

New variables: g:syntastic_debug_file, the name of a file where to write
debugging messages, in addition to adding them to the message history.

The old g:syntastic_debug is now a sum of flags:

*  1 - trace checker calls
*  2 - dump loclists
*  4 - trace notifiers
*  8 - trace autocommands
* 16 - dump syntastic variables (not implemented yet)
More detailed debugging.

Moved logging functions to autoload/syntastic/log.vim.
Cleanup debug functions.
Add a function to dump option variables.
Update: shellcheck now has a gcc-style output mode.
Shellcheck now outputs byte counts.
Remove a few forgotten references to syntastic#makeprg#build().
Merge branch 'debug'
New command :SyntasticSetLoclist.
Minor cleanup.
New checker yamlxs for YAML.
oclint does not have -text option any more
removed executable() check so as to support different perl versions using perlbrew (I.e. local version different to system version) via "let g:syntastic_perl_interpreter=/usr/bin/env perl"
Merge pull request #875 from colinmkeith/syntaxchecker_yamlxs

Support for perlbrew.

Remove executable() checks so as to support things like `let g:syntastic_perl_interpreter='/usr/bin/env perl'`.