EnhanceSound when switching to fishing mode

[CommitCrime]

Hi!
Started to use your Addon yesterday. Mainly fishing at Margoss's retreat.
Found it a bit weird, that the music always goes up when the fish cast is over, just to be silenced 2 seconds later when i cast fishing again.

Maybe the calls to Enhance/RestoreSound should be done when entering/leaving Fishing Mode (i.e. at /gofish).