Minimally support repeated values

Minimally support repeated values, which currently cause an exception in
the gen'd proto code.

Minimally means treat them as optional:
- if the repeated exists 1 or more times, emit the first value
- if there are no values, emit a null

Plus a little cleanup:
- move the example proto to test/resources
- remove the .idea files (already .gitignore'd but had been checked in)
Merge pull request #3 from smparkes/master

Minimally support repeated values