Remove empty test files
Sort test file names in the side bar
Clean up NSExpression test
Remove unused gnustep crasher macro
Add test for [NSFileManager enumeratorAtURL:... with nil URL
Add test for +[NSURL fileURLWithPath:isDirectory:]
Merge remote-tracking branch 'apportable/master'

Conflicts:
	FoundationTests.xcodeproj/project.pbxproj