Make SyntaxCheckers_*_GetLocList() dictionary functions.
Pass a reference to the current checker to syntastic#makeprg#build().
Add an optional 'redirect' argument to CreateAndRegisterChecker().
Change the sh checker to use the new dictionary functions.
Add a new registry method getLocListRaw() (needed for the sh checker).
Helper script efm_perl.pl is no longer needed, error formatting is now
done in a preprocess function.
g:syntastic_perl_interpreter is now a list. If set to a string,
the value is still used for backward compatibility, but a
deprecation warning is issued. There is also a buffer-scoped
b:syntastic_perl_interpreter.
Warnings are are now checked only if no errors are found.
