GF-14590: adds rtl property on enyo.Control

When the UI locale is a right-to-left language, the glue code
now puts an rtl property set to true onto the enyo.Control
prototype. This way, all of the widgets can easily detect if
they are in rtl mode without doing the expensive operation of
checking the CSS class.
Merge pull request #6 from enyojs/GF-14590

GF-14590: adds rtl property on enyo.Control

Reviewed-By: Ben Combee (ben.combee@lge.com)