Maxthon 3.3.4.2000

# Improvements:
* Improved the support to xunlei.com in Ultra Mode.
* Improved the memory usage in Ultra Mode.
* Increased the browser startup speed.
* Improved the extension platform.
# Fixes:
* Main Frame
- It did not support open .url files by Drag&Drop.
- It could not move the browser window by Drag&Drop.
- It could not load the icons in Side Bar properly.
* Webkit Core
- Some crash problems.
- The browser would freeze if switched the category of Quick Access pages.
- The highlight part would not disappear after closed "Find in Page".
- Extra space problem of Spell Checker.
- Context display position problem in Google search bar.
- Incomplete language context in right-click menu.
- Sometimes it could not download files with Thunder Downloader immediately.
- One downloader identification problem.
* Trident Core
- There was no Navigation History menu in right-click menu of "Back" menu.
* Inner Page
- "Open All" did not work well in Last Session page if there were some locked tabs.
* Online Notepad
- Crash problem during the syncing.
* Extension Platform
- Solved some interface realization problems.
- The problem related to deleting the extension package with multiple extensions included.