pip installable arbor catalogues (`build-catalogue` extension)

[Helveg]

A flag could be added to the build-catalogue script so that build-catalogue --python-pkg instead of a shared library produces a source distribution whose install produces:

• A shared library object built against the target machine's arbor library containing the catalogue.
• An importable code module that executes arbor.load_library("artifact.so")

To further support pip installable catalogues arbor's Python interface could load all modules that announce themselves with a pkg_resources entry point like arbor.catalogue. (To auto load all installed catalogues)

The basic workflow would be:

• Generate a build folder with a template Python package in it
• Collect the mod files and place them in the template
• Fill out the deets in the template setup.py
• setup.py should:
  • Override the install command to build-catalogue
  • Contain instructions for the module/entry-point
• Run the python setup.py sdist command
• Remove the builder folder

Maybe all of this warrants build-catalogue to become its own tool to help users manage, make and distribute their catalogues. arbcat build, arbcat list, ... looks sexy ;p