GitLab

add helper class in java to access specific functions available only in Android SDK, such as retrieving DNS servers.
Refactor wifi lock, multicast lock so that they use this new class.
Manage the CPU lock required for call in the core, instead of app's LinphoneManager.

Fix linphone_factory_get_ring_resources_dir() that did not return the correct path if the sound_resources_dir has not been set.

Fixed linphone_transports_new method + created LinphoneVideoActivationPolicy to replace LinphoneVideoPolicy

Adding new API int linphone_call_terminate_with_error_info(LinphoneCall *call, const LinphoneErrorInfo *ei) and other functions to handle  RFC3326 reason header.

* Introduction of LinphoneFactory singleton class to create
  core-independent object like LinphoneAddress or LinphoneVcard.
* Make several C structures inherite from belle_sip_object_t class:
	* LinphoneCore
	* LinphoneVcard
	* LinphoneAuthInfo
* Creation of the LinphoneCoreCbs class that enable to store the
  callbacks used by LinphoneCore.