Add the ability to filter which resources to load

Right now, the load mechanism pulls in all files in given resource directory. For some use cases this is not enough -- at the moment the easiest way to do a selective import is to move only the dump files you want into a separate directory and load from that.

I'd like to introduce the ability to define a set of glob patterns which would be used to select or reject which dump files to load.
These could be specified in a profile, like:

profiles:
  prod:
    include: prod_*.json
    exclude: pre_*.json

Or at the command line, as in stacker roles load --include '*_admin.json' --exclude 'temp_admin.json'.

Start by tracing the load mechanism and the stacker roles load command, then inspect how profiles and resource directories are read. The work is done when include and exclude glob patterns can be supplied in profiles and on the command line to select which dump files load.