This sub-project consists of a few files with logic extracted and modified from Google's Protocol Buffers. They are
used to support a protocol buffers codec in rest.li.

The reason we do this instead of depending on Protocol Buffers directly, is that a direct dependency causes
some runtime incompatibilities with dependencies of pegasus that depend on/generate code using old protocol
buffer versions.

We should ideally delete this code and move to directly depending on the official Google Protocol Buffers Library
once we have figured how to solve this problem.