#10 enhanced search features

[Dan Snyder]

Here's a patch that enables some extra search
functionality.

1) search by file modification time
2) filter results by date, length, or bitrate

All features work but I can't quite tell how to hand over
results to main.php so it highlights only matching songs
when searching Artist or Album. This works as usual
when searching song titles.

Could you point me in the right direction?

[Dan Snyder]