LT-13693 Remove unused references from projects and files
 * Remove reference to ManagedLgIcuCollator (JIRA issue
   FWNX-296 records that ManagedLgIcuCollator is temporarily
   disabled on Windows.)
 * Correct how allCsharpNoTests target gets created
   (FieldWorks.targets contains target allCsharpNoTests which
   is auto-generated. Unfortunately, it contained three
   dependencies which were only used in unit tests.)
 * Remove obsolete NAnt build files. (They were causing
   confusion when trying to detect source of various files
   in Output\Release.)

Change-Id: I93ce8f6f9f7438bb49b0dc40dfa275b050212b0b