The MXS_MODULE structure of each module is now globally exposed by the
`get_module` function. This allows the module information of any module to
be queried.
This information can then be used to validate various things but the main
goal is to provide a way for modules to declare accepted parameters in the
MXS_MODULE structure. This will be done in a later commit.
Also the function documentation is now in the header file. This should
make it easier to read.
33d98830dd