isManagementInterface?

Hello,

it would be nice to have a _zmsglobals-method to check, if one is in
management interface or not. The existing _globals.isManagementInterface()
can not be accessed in SpecObjs-DTML etc. 

In addition the method should more generic - to check the URL just for
'/manage' is not adequate, because new opened windows for link-browsing,
tex-formula-editor, custom-char-functions etc. may not have it in its URL. 

At the moment i do not have a good idea, because 'manage_lang' will be gone
from REQUEST in future releases (?!?) resp. it is always set in
/dtml/zms/f_standard_html_request (?!?).

Regards, Christian Meier