Improve "Detect Moved Code" file <select> search filtering

[fekblom]

The library used for adding the search functionality to the <select> list, chosen.js, does prefix matching per word. This makes it really tricky to find a file by name since the file path is just one long "word".

For example, in the list:

• long/path/to/file.cc
• another/really/long/path/to/some/otherfile.cc

Searching for 'file' will give no matches. I would like for it to find at least 'file.cc' or possibly all entries for which the query string is an infix match of the file component part of the path (in this example both items of the list).