Use includeFilter and excludeFilter to specify what Avro files to use

[mariussoutier]

I came across a case where I had a couple of Avro schemas that I don't want to generate classes for, so I added the ability to exclude / include specific files. Per default all goes through.

By the way, did you remove sbt-scripted?

[julianpeeters]

Looking great. Nice use of sbt's existing FileFilter :) I'd merge this in, but since it's to master I want to make sure it's as well-tested as possible -- here meaning restoring the scripted tests, or at least setting a single scripted project up to test this new feature.

[mariussoutier]

Damn I deleted the tests I wrote on the old version, but essentially I checked for existing and non-existing files when excluding certain AVDLs.

[julianpeeters]

Ok great