[Fix issue #2] Add `panGestureEnabled` property.

**Deprecations**
* `panEnabledWhenSlideMenuIsHidden` is deprecated.
Update demo to show how to use the new `panGestureEnabled` property.
Update README for the usage of `panGestureEnabled` property.
Add a link to issue #2 in README.
Bump version 1.1.3
Bump v1.1.3