Move the project/user association management code into the management area

• config_defaults_inc.php
  (g_project_user_threshold): new config option controlling the access level
  require to add and remove users to/from projects

• manage_proj_edit_page.php: Add code from proj_user_menu_page.php to display
  users associated with the project and allow you to manage them.

• core/html_api.php
  (print_menu): remove 'Users' link from the main menu

• core/project_api.php
  (project_get_all_user_rows):

  • fix an incorrect comment
  • remove references to non-existent function parameters
  • return the array sorted by username

• core/utility_api.php
  (multi_sort): new function that sorts a multi-dimensional array by a given key

• lang/strings_english.txt
  (s_create_new_project_link): new string

• manage_proj_user_add.php: new file (modified from proj_user_add.php)

• manage_proj_user_copy.php: new file (modified from proj_user_copy.php)

• manage_proj_user_remove.php: new file (modified from proj_user_delete.php)

• proj_user_add.php: deleted file

• proj_user_add2.php: deleted file

• proj_user_copy.php: deleted file

• proj_user_delete.php: deleted file

• proj_user_menu_page.php: deleted file

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@1813 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9