Bump version number to 2.0.0b3
travis: Turn on py34 testing
load: Extract repeated error check
load: Return object if already loaded even when offline

Related to #129
load: Improve error message

Related to #129
offline: Split out connection controls
session: Move session.connection_state to session.connection.state
connection: Change set_connection_type into 'type' property
connection: Change set_connection_rules into multiple properties
connection: Docstring fixes
docs: Fix typo
docs: Fix link
session: Improve connection state docs (fix #129)
docs: Minor quickstart improvements
examples: Wait for correct connection state

Related to #129
docs: Fix typo
docs: Fix another typo
docs: Fix a number of typos
session: Reorder methods
offline: Fix typos