#8 1. Commit blobs done
   2. Update tree done !
   3. Make a commit object - done
   4. Update HEAD - ongoing
   5. Post-processing - ongoing

jQuery promises look really nice, especially in combination with pipe:
[Select dialog] -- provides list of blobs to commit --> [Commit blobs] -- provide the list of blobs with sha --> [commit tree] -- treee sha --> [commit object] -- commit sha --> Update HEAD !!! Looks perfect !