[Rprotobuf-yada] [patch] More graceful error handling, support import patterns other than .proto$, and add simple repeated field unit test

[Murray Stokely]

Hi Dirk, Romain, et al.

Turns out I'm able to use your modified RSourceTree just fine so I
won't need to make any significant changes to the way you import the
protocol buffer definitions, but I do have a small patch to make
things a little easier.

   http://www.freebsdmall.com/~murray/patch_by_Murray_rprotobuf_r406.diff

While here, I added a test for the simple issue we used to have with
RProtoBuf v0.1 but which you subsequently fixed.

          - Murray