Add a cake.conf for the raspberry pi
If the number of processors can't easily be determined from /proc/cpuinfo then default to one.

This means that cake works on the Raspberry Pi now.
--file-list now lists all files (was missing some .c/.cpp files). --include-git-root now adds the git root using -I (non-system) rather than -isystem (system files)
Documentation update to reflect that --include-git-root is now enabled by default
Get cake to define a CAKE_PROJECT_VERSION macro at build time.  cake determines the actual project version by running the PROJECT_VERSION_CMD which can be something as simple as "echo myproj-888.888.888-1" to a complicated git command.
Add some default cake project version commands to the /etc/cake.conf
Better error handling in the project version command for centos 6
Use pkgit to provide the project version number in the centos 6 cake configuration
Merged from upstream