The Core Module. All Gneiss modules depend upon it.
You will need other files to run a minimum Gneiss M-MVC frame. See the examples (soon to be listed) for more.
Gneiss::core expects to be located in ./modules/core/
Note: All Gneiss modules use a namespace that reflects the folder structure. This both enables the autoloader to work and keeps filenames non-dependant on other modules.