Nth PR on develop branch for easybuild-docs, for N=6


Hi @boegel, @stdweird,

I think the new structure is better visible at this point; can you validate?
Best way to visualise it is this one: http://easybuild-docs.readthedocs.org/en/develop/
However, giving the feedback in github style over here would help it advance faster, I guess...
we should flesh this out a little bit:


First, you search which easyconfigs are available for WRF, using `--search` [include ref to section], and you select one based on the software version, toolchain, etc.

Using the selected easyconfig file, you can get an overview of the planned installations using `--dry-run` [include ref].

Finally, building and installing WRF is done by specifying the matching  easyconfig file in the `eb` command line, and using `--robot` to enable dependency resolution. That way WRF and all of its dependencies are installed _with a single command_!