Add missing funcsigs package to source release

The vendored funcsigs package was not declared in the setup.py package
defintion so failed to be included in the source distribution.
Prefer __wrapped__ attribute convention

From Python 3.3 the standard library has adopted the convention of
adding a __wrapped__ attribute to wrapper functions with the orginal,
decorated, function. Begins now uses the __wrapped__ attribute rather
than its own convention of the __signature__ attribute for the function
signature of the decorated function.
Add roadmap for beta release of docs

A draft roadmap for features and modifications for begins before it's
ready for a beta release.
Version increment for 0.2 release

Update version number for next PyPI release.