unsetAll(), nullifyEmptyStrings

unsetAll is a convenience method that will remove all elements specified by the `$keys` array.

nullifyWhiteSpace will convert all strings containing only whitespace to null. Usefull for db inserts when you want to insert null and not an empty string.
Since you can do `unset($array['boo'], $array['foo'], ...)` already, this function just turns that into `unsetAll($array, ['boo', 'foo'])`. But not sooo different, could save you some characters but if called in a low loop will probably be slower (don't quote me on that).