Also clear the cache of referencing modules
Various bug fixes and caches
Message box when no dependency exists
Update Jars containing 
https://github.com/ceylon/ceylon-spec/commit/862f828fb8fa061b946f6bb021e73336f7c8d9f2
and 
https://github.com/ceylon/ceylon-compiler/commit/ee9d008bab84ae9ca749bb1cc01b31888ab96dea
in order to fix #793