Assortment of fixes regarding OgreOggSoundRecord class

[sercero]

• Improved some API descriptions
• Add a _checkExtensionSupport() that prints the OpenAL extensions available in the same way as Ogre does with OpenGL
• createRecorder() never saved a pointer to the created Recorder in mRecorder (causing segfault when trying to stop recording)
• Moved getCaptureDeviceList() from OgreOggSoundRecord to OgreOggSoundManager (OgreOggSoundManager is a more logical place to manage this)
• The recording feature was only available on Windows... now it is also available in Linux too.
• Changed header to have more consistent bit widths (could be improved if we demand C++11 compliance)