Meshmoon: Make JSON a first class citizen in Tundra. New rendering config.

* Adds `CoreJsonUtils.h` that has various functions to parse JSON to `QVariant` and to serialize `QVariant` to JSON.
* Adds new dependency QJson http://qjson.sourceforge.net/
 * Dependency build implemented for Windows. 
 * Mac and linux needs to be implemented before this can be merged as this is a core dependency.
 * Currently uses my fork because I had to do windows fixes. Sent to upstream here https://github.com/flavio/qjson/pull/34
* New rendering config using JSON.
 * Single file that has both Ogre resource locations and Ogre plugins.
 * Single file for all platforms. Has `Common` sections that get processed on all platforms and platform spesific sections.
 * Removed old ogre *.cfg files.
* Ability to pass in custom rendering configs with `--ogreConfig` startup parameter.
* Cleaned up OgreRenderingPlugin and Renderer code.

**Note:** Do not merge this before the QJson dependency build/install is implemented for OSX and linux. It might actually be easier there as seemingly the library is in linux package managers and in macports/homebrew for OSX, see more at http://qjson.sourceforge.net/build/