Revert "parse "of" as KEYID "of""

This reverts commit 41d145d1fd7395754d184e9d76b59917dbcf46fe.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/branches/v8.4@16596 85f007b7-540e-0410-9357-904b9bb8a0f7
Revert "KEYID token makes parsing more robust in face of notations"

This reverts commit f4d5a7691e3eb76a1079df2276c25f277eaa2e3b.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/branches/v8.4@16597 85f007b7-540e-0410-9357-904b9bb8a0f7