which can be defined to call C functions with defined parameters.
* Parameters are RNA properties, with the same types.
* Parameters are stored in a ParameterList, which is like a small
stack with the values. This is then used to call the C function.
* Includes Python integration.
* Only one test function is part of this commit, ID.rename.
* Integration with the editors/ module is not included in this
commit, there's some issues to be worked out for that still.