End 0003638: The bugtracker should be able to produce a changelog.

A changelog_page.php

• Change log page.

M config_defaults_inc.php

• Added threshold for access level required to view change log.
• Private issues will only be visible to the appropriate access level.

M set_project.php

• If current project changed while in changelog page, don't go to main page.

M core/html_api.php

• Add changelog to the menu if the user has the appropriate access level.

M lang/strings_english.txt

• Add required strings.

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@2566 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9