Allow admin configuration to remove tokens if no replacement value can be generated

When using this module to create a filter, if data field is NULL, it's rendered with un-parsed token.

Problem:
By default the module TokenFilter calls function token_replace in function _token_filter_filter_tokens . If a token does not contain a replacement value, the token name is still spat out in the field.

Solution:
token_replace is defined as token_replace($text, array $data = array(), array $options = array()).
In the options aray, there is a 'clear' option which is

"A boolean flag indicating that tokens should be removed from the final text if no replacement value can be generated."

.

We need to provide an Option that allow admin who is configuration an "filter" is enable this or not.