Add support for buffer-local b:syntastic_checkers var.
This allows the overrides to work
Update help file for b:syntastic_checkers
Merge pull request #532 from dbarnett/per_buffer

Add support for buffer-local b:syntastic_checkers var.
Merge pull request #537 from brendanjerwin/fix_coffeelint_options

Fix CoffeeLint parameter overrides