replaced usage of 'requestContext3DMatchingProfiles' with custom implementation

Unfortunately, that AIR method is still buggy. See:
http://forum.starling-framework.org/topic/potential-problem-with-the-starling-profile-auto-selector
and
https://bugbase.adobe.com/index.cfm?event=bug&id=3757050
fixed missing argument check (closes #541)
fixed that fatal error box was not scaled right in some situations
changed 'reqeustContext3D' call to be backwards compatible again
now handling invalid profiles, too

e.g. "baselineExtended" is only available beginning with AIR 3.7