Testplan Bugfixes and Features

Fixes:

• Change download URL to https://www.linphone.org/technical-corner/linphone
• Crash on contacts list when deleting a friend and trying to load logs.
• Message status behaviour : Resuming status when changing logs, cursor shapes updates, bind the resend message action to error icon
• Synchronize settings and main presence.
• QML Crashs on fullscreen

Features :

• Add utilities in fullscreen view (media quality, security, mutable speaker)
• Show fullscreen on the current call screen
• Show Display name of participant in conference
• Participants in conference are mutable