Removing dangerous locks in setSession
Adding support for automatic saving.

A TimerTask has been added to automatically save session data each 30s.
FIX: Added more checks for setValueAt method to avoid errors.
FIX: Better handling of selected conversations in SummaryPanel to avoid
errors.
Removed printing stacktrace when a SocketTimeoutException occurs.

The exception is handled by ConnectionHandler, which logs a severe
event.
Cleared lock functions in FrameworkModel/setSession.
Cleared the locks in FrameworkModel/addConversation.

Remove the big try/catch and the unneeded readLock.
Added a if to avoid calling functions if the writeLock is not possible.
Indentation update.
Changed use of System.err to _logger.severe.
Updated FrameworkModel/setConversationProperty

Use of a locked variable.
Updated FrameworkModel/addConversationProperty
Updated locks in addUrl
Updated locks of setUrlProperty
Updated locks of addUrlProperty
Updated locks of addCookie
Updated locks of removeCookie
Updated locks in FragmentsModel/addFragment
Updated locks in FragmentsModel/setSelectedFragment
Updated locks of
FragmentsModel/FragmentConversationModel/setSelectedFragment
Updated locks of FragmentsModel/FragmentConversationModel/fragmentAdded