exclusions from globbing

Problem description
I have run into a situation that seems not to be handled by sphinx globbing. I have two toctrees that use globbing to define their contents. The intent is two sets of non-overlapping pages, one per toctree. However, I cannot get the globbing to avoid including some pages in both.

Potential solution / feature request
It would be nice to have a mechanism for excluding some patterns in addition to including them. For example, one might be able to write something like the following to include all the docs minus the details:

:glob:
docs/*
!docs/details_*

Recognizing that a leading character to select exclusion (! in this example) might conflict with an existing filename, it seems that there should be an option to redefine it:

:exclusion_char: !

Perhaps all of this is already implemented and I have just never run across it. If not, I hope you will consider the idea, as it would make globbing more broadly useful, especially in situations where moving files about is not possible.

Start by tracing Sphinx's toctree globbing entry point and the tests covering glob-based toctrees. Determine how inclusion patterns are resolved and how an exclusion syntax could be specified without conflicting with filenames; done means separate toctrees can include and exclude the requested page patterns.