logging improvements, small reorg, and support as a core-provider

* peerconnection directory, which defines the webrtc module is now called webrtc
* The Log class now takes the tag as a constructor parameter (e.g. `var log = new Logging.Log('test_module'); log.info('test info log')`)
* `logger` is now `logging`, and freedom module fixed, tested, and accessed by 'core.log' provider. 
* Logging available to core-providers
* Logging used in webrtc and the uproxypeerconnection provider, and also in the freedomchat sample app
* Moved non-freedom uproxy-library code out of freedom-for-*-for-uproxy. It is now loaded by the core runtime environment (see freedom/samples/freedomchat-chromeapp)
* Moved/rationalized location of freedom code into freedom-directory.