Version 1.5.3

• Add protobuf-c.{ch} and generated data access classes from *.proto files to simplify library usage and remove the dependency on protobuf-c when installing the library via Git Submodules.
• Add Homebrew Bundle to manage non-Ruby dependencies from Homebrew.
• Add XcodeGen to generate the Xcode project file. This way, project all customizations are contained within a single project.yml file.
• Add bootstrap, setup, cibuild, and deploy scripts to encapsulate standard routines. Each of these scripts is responsible for a unit of work. This way, they can be called from other scripts. This not only cleans up a lot of duplicated effort, it means contributors can do the things they need to do, without having extensive fundamental knowledge of how the project works.
• Add README.md file to describe setting up and building processes.
• Move source and test files to corresponding Sources and Tests respectively.