[tracker] (11 commits) ...libtracker-data, -common: Fixes after Martyn's review

[Philip Van Hoof <pvanhoof src gnome org>]

Summary of changes:

  6c86078... Changed the ontology to have tracker:Ontology and nao:lastM (*)
  88885d3... refactor: renamed tracker-ontology to tracker-ontologies (*)
  6a52176... libtracker-common, libtracker-data: Introduce TrackerOntolo (*)
  ad04eb5... libtracker-common, libtracker-data: Added ontology validati (*)
  3d97acb... libtracker-common, -data: distinguish between entities that (*)
  f4f2d2c... libtracker-data: Support for modest ontology changes (*)
  b8cfe3e... libtracker-data: Bugfix coping with modest ontology changes (*)
  e76cf43... libtracker-data: Update the nao:lastModified of the tracker (*)
  e351454... libtracker-data: Make the unit tests work (*)
  2b50eeb... libtracker-data: Nicer debugging messages during alter tabl (*)
  cff064e... libtracker-data, -common: Fixes after Martyn's review (*)

(*) This commit already existed in another branch; no separate mail sent