auto-reload config under plugins object

with backward-compatibility and deprecation message
including built lib
update readme to reflect moved config
Merge pull request #18 from es128/patch-1

auto-reload config moved under config.plugins object
Add license.
Merge branch 'master' of github.com:brunch/auto-reload-brunch

Conflicts:
	README.md
Release 1.6.1.
Add src/ and changelog to npmignore.
Fix styles reload in brunch 1.6.4+.
Release 1.6.2.