Import slidingmenu library

Library: https://github.com/jfeinstein10/SlidingMenu
Add fading of content view to slidingmenu library

Referenced:
https://github.com/carlbenson/SlidingMenu/commit/dde11ddb8f2891687f0113aa949a26a1f84b163a#diff-0a9a1c62fc1ac88e8b2c970d2e125f0dR795
Apply base slidingmenu