Added SecureWebSockets module

Added snapshot of GitHub project as an Android library module:
https://github.com/preplay/SecureWebSockets
HEAD: 0f0c228
Updated to use SecureWebSockets

Removed AndroidAsync library because it didn't support TLSv1.1+.
Converted code to use SecureWebSockets instead.
Fixed bug where failing authentication would not result in a new
prompt.