Added support for drawers opening from the top or bottom of the screen.

[ericpalakovichcarr]

This primarily adds support for specifying top or bottom in addition to the existing left and right options for the side prop. Here's a rundown of what's changed:

• In the library itself:
  • Variables like left have become a more generic version, like length
  • Added the isLeftOrRightSide() function, returning true if the drawer opens to the left or right side of the screen. Otherwise it opens top or bottom. It's used for things like determining which way the drawer should animate open, or whether to use gestureState.dx or gestureState.dy for example.
  • Added the getDeviceLength() function to be used in place of this.state.viewport.width (since top or bottom would need to use this.state.viewport.height instead)
  • Added the getGestureDelta(gestureState) function to be used in place of gestureState.dx (since top or bottom would need to use gestureState.dy)
• Updated README with the new top and bottom options for side
• Removed the .idea folder from the repository (let me know if this is a bridge too far)
• Updated the RNDrawerDemo project for the new top and bottom options.

Let me know if this needs anything else before it can be merged.

[dotansimha]

👍
any news on merging this PR?

[dotansimha]

@BigSassy, just tested this PR in my project - it works great!! thanks!!

[ericpalakovichcarr]

@dotansimha You are very welcome 👍

[timkendall]

This is spicy. Thanks for implementing - exactly what I need!

[michaelkirschbaum]

Tested this. Looks good 👍

[rt2zz]

this is fantastic, sorry for taking so long 👍 in we go :)