This fixes https://linphone.atlassian.net/browse/SDK-86

Remove useless jazzy stuff + Rename ENABLE_JAZZY_DOC option to ENABLE_SWIFT_DOC + Fix line returns in swift doc template.

Add test to verify behaviour when multiple INFO messages are sent back to back by both parties almost at the same time.

- Delete classes IdentityAddress and ConferenceAddress
- Make Address a derived class of HybridObject
- Use smart pointer for objects of Address type whenever they need to be handled by the applications

Add property to disable deletion of empty chatrooms
Enable compiler option '-Wunused-parameter'
Fixed possible null pointer exception in Java wrapper for Android
Update copyright notice in wrapper files

Allow building without libxml2 and sqlite3, to minimize binary size. This drops features (friendlist storage, presence).

Improved callback header, fixed test that may crash if it fails, moved conference scheduler state enum as child of conference scheduler

Assign to every participant a sequence number. The first time a participant is added to a conference, its sequence number is 0 and it is incremented by one every time the conference is updated. The sequence number is sent to every participant as a parameter of the ics field ATTENDEE
Add conference scheduler cancel conference
Add test to verify edition of conference while it is active

- Remove used deprecated functions on video_definition and add missing linphone_core_set_preview_video_definition_by_name
- Add an API to get recommended video definitions to make a difference between what definitions Linphone support, and what definitions that are suitable for a widest set of hardware for all video codec implementations in order to excludes some very high definition formats that are unlikely to work unless specific hardware or codecs are used.

- Remove used deprecated functions on video_definition and add missing linphone_core_set_preview_video_definition_by_name
- Add an API to get recommended video definitions to make a difference between what definitions Linphone support, and what definitions that are suitable for a widest set of hardware for all video codec implementations in order to excludes some very high definition formats that are unlikely to work unless specific hardware or codecs are used.

- Multithreading LDAP search in cpp
- Multithreading and queue management on Magic search requests
- LDAP : Tester recfiles
- LDAP : Adapt tests

Clean and rework MagicSearch
- Auto clean cache between async search (optional)
- Variable visibility
- Better data structure
- Documentation
- Shared pointers on cache
- Allow cancellation from search (in addition to providers)
- Pool of generic providers in order to allow other future implementations
- Searches processes done on Iteration main loop to follow simple state transitions
- Keep synchronous mechanism working

- LDAP : Make search before getting results
- Fix adding results from core friends list

- Add Getter for certificate checks options
- Add debug and certificate verification options to LDAP/TLS

Add requested domain when dealing with sal to TLS handshake

- remove libgcc and libmingwex from msvc builds

- Add OpenLDAP for all platforms if enabled
- Add libraries for Windows
- rename linphone_core_get_verify_server_certificates(LinphoneCore to pass wrapper multiple definitions names
- Windows : remove forcing mingwex and gcc dependencies
- Add switches when enabling LDAP

Add linphone_magic_search_get_callbacks_list to public API

 - Update python wrapper generation to genrate LinphoneWrapper.cs with a
   full documentation.
 - Update cmake to generate a html doc site with docfx for C# wrapper
 - minor fixes in lib documentation

* Fix links to classes, enums and enumerators for every doc engines.
* Document “linphone” namespace in order top-level enums be indexed by Doxygen.
* Make @bctbx_list Doxygen macro to not generate code in HTML documentaiton.
* Fix several invalid reference in the C API documentation.

Improvements for generated documentation for wrappers + removed useless code in JAVA wrapper related to factory

Added @tobefreed tag to add to returned values that are allocated on the stack and needs to be freed by the app/wrapper

When participants are added to a local conference, a remote conference is created that allow the remote participants to receive notifications about newly added participants and other events if the event conference package is enabled
Delete private classes of LocalConferenceEventHandler, RemoteConferenceEventHandler, Participant, ParticipantDevice, Conference, LocalConference, RemoteConference, RemoteConferenceEventHandler, LocalConferenceEventHandler
Send 200OK to subscribes whose state is terminated and expires field is set to 0
Create audio video conference tester whose task is to verify conference behaviour

More work on documentation + modified JAVA wrapper to ensure all returned arrays are never null even if the C API says maybenil