It isn't very often that a Menu Manager template will be called within a
template. However, It may be useful for some.

Currently when you export a theme only Menu Manager Templates that are called in
the page Templates are harvested. If a MM template is called inside another MM
template the nested template is not exported.

I attempted to hide a call for the nested template inside the regular page
template like this: {*cms_module module='menumanager' template='nested'*}. It
did export the nested template, but when it is imported the naming structure was
not changed for the call in the MM template. It stayed as "template='nested'"
when it should have been changed to "template='themeName : nested'"

If I pre-plan and name the nested template call with the name I will use for the
theme I can get it to work. But this FR would avoid having to do all the fancy
foot work.