Retry count inside the goto was retrying forever
Allow completely empty URL template

This is needed (in conjunction with #40) for generic interfaces to be of
any use at all.
Support for generic interfaces

Fixes #63.

Now people can have all the boring CRUD Web APIs they want and they only
need one interface. :trollface:
Add docs for generics & fix formatting
Merge pull request #70 from bennor/generic-interfaces

Generic interface support