Fixed typo
Don't let the selected artist ever be null

This fixes a crash when changing the library source path
Fix the playlist item title width
Revert "Fix the playlist item title width"

This reverts commit 4354cb2564cbb0fa653342a7250be3255242897d.
Fix the playlist item title width
Do an update check every 2 hours instead of 15 minutes
Updated screenshot
Skip the initial screen update
Do it LINQ style
Initial hack on the artwork fetching
Fix the release lookup link
Intelligently cache online artwork searches
Make the fetching fire-proof
Fixed a typo
Move the semaphore to its own class and add some tests for it
Fix the artwork fetcher exceptions

HttpClient returns a HttpRequestException, not a WebException (Thanks MS for not documenting exceptions on async methods)

Additionaly, the release id lookup can fail with a "Not Found" status, which is completely valid in this case, so don't throw an exception and just return null.
Just return the cache key when fetcghing an artwork online
Release the semapohre if we return early
Release the semaphore under all circumstances and queue all cache operations
Properly escape the search query