Update src/nl/arendjr/slidingmenulayout/SlidingMenuLayout.java

Added the following code in opemMenu and closeMenu, before creating a new Timer object
if (m_timer != null) {
    m_timer.cancel();
}


To avoid a bug that occurs when continuously invoking open/close Menu quickly the timer runs forever and the menu hang.
Update src/nl/arendjr/slidingmenulayout/SlidingMenuLayout.java

- Add support for the menu to be on the left or the right side of the screen
- Convert all hard-coded values to constant variables
- add toggleMenu() method
Update src/nl/arendjr/slidingmenulayout/SlidingMenuLayout.java

Just fix some copy and paste errors
Update README.md
Merge pull request #2 from iTech-Developer/master

Fixed a stability issue and few enhancements