Duncan Coutts authored Mar 13, 2016 and Mikhail Glushenkov committed Mar 17, 2016

One for testing if globs are trivial, as in they're constant strings
without the possibility of matching more than one thing. This can help
with making better error messages.

Another util for matching file globs in the rebuild monad, and
automatically monitoring the glob.

(cherry picked from commit 4365bcb1)