Do not send reINVITE if conference has layout none and the participant was added while the call was establishment

Stream capability stores the informations coming from the conference event package.
Stream availability states whether a stream is available for a given participant
Add callbacks to notify clients when changes are done
Fixed ljb redefinition in generated JNI file for Java wrapper

The conference server or participant holding the conference will always send a reINVITE following a request from a client to toggle video settings in order to keep him up to date regarding new streams that have been added while his/her video was off

- factory API to get/set the cache dir
- rename get plain file function to make more explicit that the function create a file
- empty cache on core stop
- belle-sip dir manipulation API moved to bctoolbox

Julien Wadel authored 3 years ago and Andrea Gianarda committed 3 years ago

- Get Native Window ID from participant.
- Add Window ID creation API for filters.

The conference server tries to add them as soon as possible (i.e. in the IncomingReceived call state). At this stage the participant device is in state ScheduledForJoining.
Once the call reaches the StreamsRunning state, the participant device state will move to Joining is ICE is disable. Otherwise, the server will wait for the ICE reINVITE before changing the participant state.
The server also sends out an update in order to offer the right streams based on the chosen layout.
The participant device state will ultimately move to Present once the client accepted the server offer and the other participant are notified of the addition of the participant device.

Restore previously created conference after server restart by looking at conference informations stored in the DB

Add complex test to reproduce a complex SIP race condition, now fixed in belle-sip.

Fix crash on setting remote address in call log.

Deprecated some APIs & created new ones to unify naming + workaround in Java wrapper to create duplicates if needed so Kotlin will wrap some enableX/xEnabled as properties properly

Do not allow remote participants to change conference layout

Apply more fixes to video toggling during conference

target_link_libraries() instruction was repalaced by target_include_directories()
to make build on Yocto to pass.

(cherry picked from commit 7776abdb)

This reverts commit 181d3d95.

Do not destroy conferences created on server

Fixed issue when sending invitations through ConferenceScheduler when chat room params is set to use Flexisip backend

Reworked scheduled conferences creation & conference info sending API using new ConferenceScheduler object

Set organizer as admin and allow him to remove participants
The address of me when creating the conference from an op is the to of the op itself

- do not create any intermediate/dummy conference
- do not start a call to create a conference to allow creation while in a call