Add globber pattern support to the #load directive

[gitfool]

Following up from #1726, add globber pattern support to the #load directive. This would be useful for loading a local directory full of scripts, similar to what #load nuget: does after installing the package.

Example usages:

#load scripts/*.cake // legacy
#load **/*.cake
#load local:?path=scripts/*.cake // uri
#load local:?path=**/*.cake

I'll submit a PR when I get some time in the next week. 😉