Basic additions for auth.

Conflicts:
	py2neo/core.py
set_password
Fixed up and commented password module.

Conflicts:
	py2neo/core.py
Added newline
Pass URI into auth functions, not ServiceRoot.
Removed old function
Simplified API

Conflicts:
	py2neo/__init__.py
	py2neo/core.py
Fixed conflict
Fixed conflict
Merge branch 'release/2.0.1' into feature/auth2

Conflicts:
	py2neo/core.py
All tests now passing for 2.2 with auth (not 100% coverage)
Doc updates for auth.
RecordList.one
Updated docs for env vars
Auth docs; renamed neopasswd to neoauth
Updated version and index page