Simplified the method invocation
Added OpenAL Soft library for sound effects.

Added WAV resource loader.
Non-existing resources are now logged as errors in the resource manager.
Fixed bug where the we supplies a this parameter in the constructor of the model object

This will result in an invalid pointer to the model listener, causing
weird memory problems.
Added configuration for sound volume. Moved OpenAL specific code from the base SoundEffect class.
Fixed bug.