Packaging and config consolidation

[vilmibm]

hi!

this PR addresses #15. It:

• Adds a setup.py file so ttbp can be installed with pip
• Consolidates a bunch of global variables in a new file, config/__init__.py
• Moves bin to ttbp and adds __init__.py to make it a package
• Adds back the chatter module and inlines the json file as a python dict as a default (can be overridden by a json file in endorphant's home directory)
• Cleans up a few python things
  • not shadowing dir function
  • using relative imports
• Adds support for the new /var/global directory on tilde.town and use it instead of the source directory to write persistent stuff

It is not intended to have functional changes for users.

I've tested it locally on my computer and it's all working. I'll test it out for my own existing ttbp installation tomorrow.

I have some questions!

• can _ttbp.py be deleted?
• is it okay that I inlined the ascii banner?

[modgethanc]

Thanks so much for your work here!

_ttbp.py can be deprecated once we have a better environment on tilde.town for users to run the most recent stable version and not deal with buggy/incremental updates, which this PR puts us in a much better place to set up. I'm also fine with the ASCII banner being inlined; that was sort of an arbitrary decision on my end when I was putting it together outside of a python file :)