Reworked LocalStorage
created a second table to store extended contact information
extended the add_contact_dialog.ui
aliases given either in the add_contact_dialog or implicit
  via tox dns entries are added to the contacts on adding
uris are now also marked up in the treeview tooltips
centralised the username and status strings (now in Contact.vala)
Renamed Local storage to MessageLog and externalised the sqlite db