allow guestrepo scale well when number of guestrepos are large.

Created originally on Bitbucket by mgurusamy (Mohankumar Gurusamy)

We normally tend to categorize guestrepos using their canonical path. And, If there are hundreds of guestrepos, we tend to work with a bunch of guestrepos that are grouped under a single canonical path. And we might want to grpull, grupdate only those guestrepos grouped under a given canonical path.

Updated matchguests function to match any path rather than just guestrepo paths.