Adds `saveNow`, a synchronous method for saving immediately. This is normally not needed, and should be avoided in the main thread.
Now properly saving changes done via the method `setEntriesFromDictionary:` which so far only saved the passed key/value pairs to memory.
Updating build settings to recommended settings.
Adding tests for property list setters, individual setter as well as dictionary setter.
Fixing issue where nil values for the parent timestamp would lead to a crash.