WebComment: escape review "title"

* Escape title of a review when displaying, including when showing
  the review form with some initial value.

Reported-by: Friedrich Hust <Friedrich.Hust@rwth-aachen.de>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
BibClassify: escape keywords in tag cloud and MARCXML

* Escape keywords in HTML output (tag cloud), as well as
  MARCXML output.

Reported-by: Friedrich Hust <Friedrich.Hust@rwth-aachen.de>
Reviewed-by: Tibor Simko <tibor.simko@cern.ch>