BibAuthorID: check for valid person ids

* In author pages check that self.person_id is an integer before querying
  for the author tables.
BibAuthorID: link visibility

* Link colours have been changed to #06C for improved visibility
  against the current background.

Signed-off-by: Minn Soe <minn.soe@cern.ch>
BibAuthorID: user feedback for page generation.

* The profile page now displays a notice when the mouse is hovered
  over the profile generation timestamp.

Signed-off-by: Minn Soe <minn.soe@cern.ch>