Removed check for enabled property in isDisplayed()

The enabled attribute should not have any connection to the visibility.
Also removed redundant visibility check.
Adding large activity.

The activity ExtremLargeActivity adds during creation 400 rows with each a Button and an EditText ui element.
Adding special characters to large activity.
Merge pull request #498 from lragnarsson/isDisplayed_fix

Removed check for enabled property in isDisplayed()
setting version to 0.11.0 for release
updating changelog
0.11 release (updates manifest)
bumping versions to 0.12.0-SNAPSHOT
Rolled back Selenium version due to "Invalid Protocol Error: None" when creating sessions on real devices.
Fixed issue with device serial being ignored for real devices.
Test added to prove issue.
Additional tests added to fully cover changed method before refactor.
Undo Selenium version rollback
Changed back to "HttpMethod" from "HttpVerb"
Merge pull request #517 from richard-stowe/master

Issue with getting physical devices by serial/udid
Update AUTHORS