Support patterns starting with a ./, fixes #1695

First stab at a fix for #1695... I wanted to get something down while it was fresh, though I'll take a look later and look for improvements. And of course, feedback is welcome. :)
It seems like the important thing about the glob (and the reason this spec exists) is that it is a relative glob starting with `.` to refer to the current directory -- perhaps the docstring should mention this?