Reimplement `tangled shell` as subclass of ShellCommand
Ensure scaffold READMEs are included in dist
Prepare release 0.1a3
Back to development: 0.1a4.dev0
Add tangled to packages list in setup
Include package data

I.e., add `include_package_data=True` to setup. This ensures
defaults.ini and scaffolds are installed.
Prepare release 0.1a4
Back to development: 0.1a5.dev0
Remove find_packages import from scaffold setup.py
Rename module to avoid syntax errors on installation
Require tangled 0.1a5 or newer
Update trove classifiers
Prepare release 0.1a5
Back to development: 0.1a6.dev0