Checker: simplify a bit its exception handler

 We use Errors.print for anomalies and other uncaught exceptions
 in the checker: this should print the same message, it is shorter
 this way, and we avoid using Errors.is_anomaly.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@16310 85f007b7-540e-0410-9357-904b9bb8a0f7
Fix some camlp5 quotations , restoring compatibility with camlp5 5.x

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@16311 85f007b7-540e-0410-9357-904b9bb8a0f7