Adds Control::setVisible(bool) and Control::isVisible() const
Changes enable()/disable to setEnabled(bool) for consistency.
Changes isEnabled() to isEnabled() const;
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
Merge pull request #641 from seanpaultaylor/next

Next
Fix invisible controls on MacOSX.
Merge pull request #644 from kwhatmough/next

Fix invisible controls on MacOSX.
Removes extraneous assertion that was crashing the forms test on exit on Windows.
Merge pull request #645 from kwhatmough/next

Removes extraneous assertion that was crashing the forms test on exit on...
Fixed encoding FBX files that have tangents and binormals
when the mapping mode is by control point.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
Merge pull request #646 from dgough/next

Fixed encoding FBX files that have tangents and binormals
Fixing font opacity and control opacity animations.  Adding a test of this.  Note to self: Don't submit a pull request until I fix up the memory leak in the test.
Fixing a memory leak and adding an opacity-animation test to FormsTest.
Merge pull request #648 from ablake/next

UI and Font opacity fixes.
Updated the main README.md
Added links to the website, forums and documentation.
Suggested that people post feature requests on the forum.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
Minor update to external-deps/README.md
Merge pull request #649 from dgough/next

Updated the main README.md
Adjust the look of the forms test.
Updated Linux libopenal.a to include support for PulseAudio backend
Fixes displaced joystick sometimes seen on start-up when using virtual gamepad.