Merge Request #6 - January Bis

Bugfixes

• Fix error message when losing a remote object (spurious “Socket disconnected”)
• Fix deadlock on service destruction
• Fix crash on session connection
• Fix multiple deadlocks on session connection
• Rewrite and fix crash when doing multiple PeriodicTask::start()
• Make obj.call<>() work on stranded objects
• Put back services() without arguments (for python)