Fix 0003120: Missing "Assign To" field on "Report Bug" screen.
Fix: Sometimes non-admin users are denied access to projects that they have
access for. This cause the project to revert back "All Projects" whenever the
user tries to set it to one of those private projects.

M core/access_api.php

• (access_cache_matrix): This function was not implemented and was not used.
  Hence, removed.
• (access_cache_matrix_user): Some of the cache indices were used as returned
  from the query without being converted to ints, and hence, were not found
  later. This was causing a bug where non-admin users were denied access from
  private projects.
• (access_cache_matrix_project): same fix as in access_cache_matrix_user.
• (access_has_project_level):
  • Removed the use of hard-coded ADMINISTRATOR access level. The
    private_project_threshold is not used.
  • The handling for the case where a user was not added to a private project,
    but had an access level greater or equal to private_project_threshold was not
    handled correctly.
• (access_get_local_level): Convert the project id to an int before using it to
  index the cache array. This is because 0001 can not be used to index 1.

M manage_user_proj_add.php

• Changed the required access to manage_user_threshold rather than
  private_project_threshold. The access right that is need is to be able to
  manage the users for the project, rather than access private projects.

M bug_report_advanced_page.php

• When the assign-to field was hidden, two spacer were added before the summary
  field.

M set_project.php

• Added support to switch the current project in report bug pages without
  jumping to main page.

M config_defaults_inc.php

• Removed a comment that claimed that $g_cookie_domain is not used while it is.

M core/gpc_api.php

• (gpc_clear_cookie): Added support for $p_domain parameter to be consistent
  with gpc_set_cookie().

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@2165 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9