Docs: clarification about running checkers when aggregating errors.
Add shellcheck as zsh checker.
OCLint: minor cleanup.
cpplint: add exit code check.
Bug fix: the result of expand('<sfile>:p:h') has to be escaped.
Escape Festschrift: getExec() needs to be escaped before being used.
avr-gcc: added syntax checker
Cleanup: avrgcc checker.
Escape Festschrift, vol. 2: add function getExecEscaped().
Add support for g:syntastic_extra_filetypes.

This is useful when registering checkers outside syntastic.
Bug fix: pilot error adding g:syntastic_extra_filetypes.
added syntax checking for .asm and .s files using gcc
Cleanup: asm/gcc checker.
Cleanup: allow more exec overrides; formatting.
Vimlint: better highlighting for `l:var`.
Vimlint: add a safety net for a bug in Vim.
Attempt to shut up "go test".
Revert "Attempt to shut up "go test"."

This reverts commit c6636f6db162bebe26a9a76a6114578f03b46424.
Second attempt to shut up "go test".
Merge branch 'master' into develop