Apply to SVN Revision 4704.
patch -p0 <bug7953.patch from mantis root directory.

Changes to fix Bug 7953:
1. Moved validation checks from pages into bugnote_add function
2. Added configuration option to allow time tracking without note text. Defaulted ON.
3. Moved calls to bugnote_add in bug_resolve, bug_close, and bug_reopen functions before
   bug_set calls in order to prevent inconsistency where time tracking without note text is OFF, user
   submits hours without a note, an error is triggered but bug status is changed anyway.
4. Added error in bugnote_add.php if bugnote_add returns false. Previous versions continued as though
   a note was added when in fact it was not.
