protobuf: resolve shared library multiple definition conflicts.

Patch to deal with protobuf problems in MacOsX
Details  : https://bitbucket.org/osrf/release-tools/issue/25
Upstream : http://code.google.com/p/protobuf/issues/detail?id=128

patch courtesy of @j-rivero
https://github.com/j-rivero/homebrew-protobuf
protobuf: fix formatting of previous commit

fixes formatting of previously committed patch to resolve multiple
definition issues in protobuf.
protobuf: file should end with a newline
protobuf: update 2.5.0 bottle.