New LED style for SoundPicker song display

Took me forever to perfect this
Hotfix for project tree sorting

Sphere projects stored on file systems other than NTFS, e.g flash drives
using fat32, had their files added in random order in the project tree.
This fixes it so the folders and files in the tree are always sorted
alphabetically regardless of the order the DirectoryInfo method returns
them in.  Also the first use of LINQ!
ProjectTree hotfixes

Wrong node was selected by doubleclick handler when folder expansion
caused view to scroll (.NET bug); also made Enter key open selected file
in tree
Merge pull request #14 from fatcerberus/master

Project tree file sorting