New application structure - move stuff around, make 'valijate' the main.
Add get_env() & noisy_get_env(). Also, typespec correction.
Bugfix in erlang-path-to-string: Handle atoms.
Fix bug/wart in get_env's handling of defaults.
Erlang: Implement 'either' & 'pipeline', and add 'member'.
Update doc. Mention get_env(). Show off complex rule combinators.
Fix bug in the 'either' implementation for Erlang terms.
Add tests for 'member' and 'either' for Erlang terms.
Add tests for 'pipeline' for Erlang terms.
Add list/array tests.
Add member+either+pipeline for JSON values, incl. tests.