Fixed a bunch of misc warnings. Mostly needed @SuppressWarnings.

The only warning I'm still not sure about is:

The enum constant CHUNK_LEN_CRLF needs a corresponding case label in this enum switch on ChunkedInputFilter.State

from AndroidAsync/src/com/koushikdutta/async/http/filter/ChunkedInputFilter.java:50

If you tell me what to do, I can add that fix in another commit.