Declares whether your application is willing to support right-to-left
(RTL) layouts. If set to true and targetSdkVersion is set to 17 or
higher, various RTL APIs will be activated and used by the system so
your app can display RTL layouts. If set to false or if
targetSdkVersion is set to 16 or lower, the RTL APIs will be ignored
or will have no effect and your app will behave the same regardless of
the layout direction associated to the user’s Locale choice (your
layouts will always be left-to-right).The default value of this attribute is false.
This attribute was added in API level 17.
(Source: http://developer.android.com/guide/topics/manifest/application-element.html)