Add stubs for methcla pro test sources
Add stubs for methcla pro test build flags
Factor out engine creation
Implement start, stop and process for DummyDriver
Add a static library project that builds libmethcla.a

This project can be included in other Xcode projects for transparently
building and linking against the library built by methcla's build
system.
Add a static library project that builds libmethcla.a

This project can be included in other Xcode projects for transparently
building and linking against the library built by methcla's build
system.

Conflicts:
	engine/platform/xcode/Methcla.xcodeproj/project.pbxproj
Don't throw exception from Methcla::Engine::free
Add test for node freeing
Improve error reporting when soundfile cannot be opened
Disable Methcla::Engine::handlePacket