json-c v0.10

`json-c` starting from `v0.11` has renamed the library from `libjson` to `libjson-c`. Debian-based systems are currently providing `v0.10` in the repository. Certain softwre builds coming from Debian  that depend on `v0.10` break on Mac OS X because Homebrew has moved to `v0.11`. 

Since it's not possible to specify a specific version of the package as a dependency when creating a brew file, I am sending a pull request here to give `v0.10` its own life.