message: [Doc] Target protobuf 2.6 in OS X build notes.
  Homebrew now installs Protobuf version 3 by default, which doesn't currently compile. Install Protobuf 2.6.x from the versions tap instead.
diff: @@ -16,7 +16,7 @@ Then install [Homebrew](http://brew.sh).
  Dependencies
  ----------------------
  - brew install automake berkeley-db4 libtool boost --c++11 miniupnpc openssl pkg-config protobuf --c++11 qt5 libevent
  + brew install automake berkeley-db4 libtool boost --c++11 miniupnpc openssl pkg-config homebrew/versions/protobuf260 --c++11 qt5 libevent
  NOTE: Building with Qt4 is still supported, however, could result in a broken UI. Building with Qt5 is recommended.
  