Update HTTP-RPC library in Android test.

Update Podspec.

Update Android client library.

Update version to 2.2.1.

Update README.md.

Update Android project files.

Update client JAR in Android test app.

Merge branch 'master' of https://github.com/gk-brown/WebRPC

Ensure that Java client passes "Accept-Language" header.

Verify Android execution on localhost; Javadoc updates.