Add wildcard support to .bsync-ignore

[jashort]

Adds comment and wildcard support to the .bsync-ignore file. Wildcard support is via fnmatch

The current format of .bsync-ignore should still work as well, but please double check the test I added.

I've been using this for a few weeks on both MacOS and Fedora Linux and it's been working as expected.

[dooblem]

Hello, Thanks for the PR. With the actual prefix exclude, when you exclude a directory, all the files in it are excluded as well.

But with a wildcard exclude, you can exclude a directory, but not the files in it.

I want to be sure there's not any problem if you exclude a directory, but not the files inside it.