Fix some bugs.

Fix detection error on user is post rate-limited.
Fix resolving entities error.
Improve performance.
Fix bug in property Count.

After removing item, Count property is not decremented.
Improve performance.

Improve iteration performance in Guard method.
Change converter method accessibility.

ToTarget/ToSource move public to protected.
Add WindowStateVisibilityConverter.
Improve timeline behavior.

Scroll lock now works correctly.
General performances are improved.
Add LICENSE.TXT .

This project is applied MIT/X11 License.
Query compiler errors are translated to japanese.
Tab configuration interface prepared.
Fix concurrency bug.
Improve performance.

Reduce memory consumption.
Warn to user when timeline is too fast.
Libraries updated.

Livet contains concurrency bugs in CreateReadOnlyDispatcherCollection.
so, I create ViewModelHelperEx and use it instead of Livet's.
Change disposable holder.
Change event listening implementation.

No longer use CollectionChangedEventListener in performance-critical
points (e.g. in the StatusViewModel). Now use Rx
Observable.FromEventPattern instead of Livet's EventListener.
Fix memory leak in InputAreaViewModel.
Smashing memory leaks.

Change ViewModelHelperEx to ViewModelHelperRx because it based on
Reactive Extensions.
many Livet.EventListeners are replaced by Rx-based event listening.