Moves Constants to the serivce package so that it would be accessible for other packages that need to access a PT name

Improves device selection via portaudio for MacOSX (hostapi coreaudio): adds the possibility to get the device transport type (USB, bluetooth, etc.) and an unique identifier. Corrects problems when: loading the same device twice (for the moment only for the same hostapi), a new plugged device is selected during a call or if the selected device is unchanged.

Fixes a failure to keep the aspect ratio of the video when switching to full screen. Attempts to remedy a multi-video display when switching between camera and desktop streaming. Tries to fix a crash in the QTKit video capture on Mac OS X. Works on addressing a unnecessary remaining of the camera on Mac OS X open.

Commits an initial version of the libjitsi library which should be fully functional with respect to neomedia/MediaService and should be usable with and without OSGi.