Enable support for exact match, begins with, ends with, contains for search

Currently when searching for a term, it will try to do an exact match, and return that one result if it exists. If an exact match doesn't exist, then it will perform a search with terms that start with the search term. The problem with this approach is that if I want to search for all terms that start with "banana", but I already have a term called "banana", then it doesn't return all the results. I hacked the module to make it work the way I want to, but ideally the search should be enhanced to support different search options: "exact match", "begins with", "ends with", "contains", there the default should be "begins with".