Allow (require?) users to specify names for PushManagers. ApnsConnection names are, by default, derived from the PushManager's name.
Updated PushManager logging statements to include the PushManager's name.
Updated docs and added a name getter for PushManagers.
Added name-related tests.
Updated the README to include the new name argument for the PushManager constructor.
Clarified that the push manager will stop taking notifications from the public queue once the shutdown process has begun.
Merge pull request #119 from relayrides/names_for_push_managers

Names for push managers
Merge branch 'master' of github.com:relayrides/pushy into close_connections_when_inactive

Conflicts:
	src/main/java/com/relayrides/pushy/apns/ApnsConnection.java
	src/test/java/com/relayrides/pushy/apns/ApnsConnectionTest.java