M core/constant_inc.php
M lang/strings_english.txt

• Added a new error for invalid or no writable file upload paths.

M core/project_api.php

• (project_ensure_valid_upload_path): a new method to make sure the supplied
  upload path exists and is writable to webserver.
• (project_create): calling the project_ensure_valid_upload_path() function.
• (project_update): calling the project_ensure_valid_upload_path() function.

M doc/ChangeLog

• Added the fix to the change log.

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@1899 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9