Updated the README for v0.3.
s/0.2/0.3/ in documentation links.
Added copyright headers where missing.
Minor documentation updates.
Updated docs for the PushManager class (whew).
Fixed links, formatting, and clarified text throughout the docs.
Renamed and clarified docs for `ApnsConnection#waitForPendingWritesToFinish()`.
Publicized `ApnsConnection` and `ApnsConnectionListener` to avoid showing handler methods without context in `PushManager`.
Merge branch 'v_0_3_documentation_updates' of github.com:relayrides/pushy into v_0_3_documentation_updates

Conflicts:
	src/main/java/com/relayrides/pushy/apns/ApnsConnection.java
Clarified the opening README paragraph and added links to the wiki.
Merge pull request #66 from relayrides/v_0_3_documentation_updates

v0.3 documentation updates