Remove XCode project and old protobuf library.
Squashed 'libraries/rsd/' content from commit 58640f6

git-subtree-dir: libraries/rsd
git-subtree-split: 58640f6b11de7dcc9864ddb47863340896d55e0f
Merge commit '74229eb385d0ac2214012031c3d55e264dfe39bb' as 'libraries/rsd'
Add and link to rsd library.