Initial Support for OpenFL based Haxe projects

OpenFL is a successor to the NME project, and includes a new project file format (always set to be project.xml, according to the OpenFL maintainer).

Patch includes UI addition to allow using OpenFL project.xml file, as well as OpenFL compilation flags.

Additionally I added some code to FakeFlexBuildConfiguration.java to return a FakeFlexDependencies object.  On my machine (Mac OSX 10.7.5. and Haxe 3) FakeFlexBuildConfiguration::getDependencies was being called, and was throwing an exception if null was returned.   Returning a FakeFlexDependencies which is also a mock object returning fake data, seems to satisfy the runtime debugger for the time being.