Fixed 4829: bugnotes of deleted users cause error

• Added prepare_api.php and implemented a couple of APIs that return info as strings rather than the corresponding apis in print_api which prints them. The print_apis now uses prepare_apis.
• Moved the strike through formatting to inside the prepare_user_name().
• Changed print_bugnote_inc.php, monitor list, relationship list, reporter, handler, bugnotes to all used the new method with the formatting.

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@3130 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9