Provide an auryn library

[sanjayankur31]

I'm just opening up this issue so that we know this needs to be done eventually - it'll be really nice to be able to use auryn as a proper library. That way, the development of new models can be somewhat uncoupled from auryn. At the present, you have to use the complete auryn source to develop stuff. This also means that one needs to keep rebasing their code and simulation repos against the upstream repo to pull in the latest commits.

[fzenke]

I agree, a library would be nice. However, it would be one that should be statically linked. One of the lasts commits (33ef4a5) adds a make target 'lib' which creates a statically linkable library from all Auryn object files, but that is just a first step. I think ultimately the building process should be reworked substantially and I have been thinking "automake" tool chain for quite some time now, but had some initial problems with the MPI bindings especially when there is more than one type of MPI implementation on your machine. Here, help in restyling the build process would be greatly appreciated.
For active development of the simulator, however, a collection of object files is still the most efficient way to compile and this build chain should continue to exist in parallel. However, a parallel build-tool-chain for the more simulation oriented end-user is definitely one of the desiderata.