Pass nil into stefon functions to work with unpatched stefon.

See circleci/stefon#16 and circleci/stefon#15.
Add what's next, donate and example project to README.
Pass empty precompiles into stefon by default.
Remove spec from wrap-reload.
Only display title when there is one.
Add in-dir and out-dir to default config.
Add validation for uri-root config option.
Spec out config validation.