fileScanner.cs

Implemented shallow ( non-recursive ) asynchronous directory scanning.
Added clause to force shallow directory scan even when recursive = true
if the directory contains no sub-folders.
Merge branch 'master' of https://github.com/snwmelt/Music
Various Patches and additions

musicMinimalUI - Minimal UI now movable, Topmost property = true and
opacity and appearance tweaked.

fileScanner.cs - Restructured to offer higher level of parallelism via
executing task with resulting string[] in Action<string[]>.

Performance gain in library.cs by restructuring to take advantage of
tweak in fileScanner.cs asynchronous directory scan.