Full parameter names in SearchApiHandler

As of this commit, the SearchApiHandler works as follows:

http://localhost:6500/api/search?s=XXX&query=Weezer&type=artists&field=artist_name&exact=true

Where:
- s: current session key
- query: search query string
- type: comma-separated list of which items to search for (e.g. artists or artists,albums or songs,videos or etc)
- field: the database field to operate on (defaults to each table's "name" field)
- exact: false will "fuzzy" search for the term, while true will find exact matches (defaults to false)