Reviewed-by: alanb, ahgross, chegar, igerasim

Summary: Cleanup of javadoc -Xlint errors
Reviewed-by: lancea, mduigou, darcy, mullan, mchung

Summary: <code> and <tt> converted to {@code }; package.html to package-info.java
Reviewed-by: darcy, chegar

Reviewed-by: weijun, xuelei

Reviewed-by: dholmes

Reviewed-by: chegar

Reviewed-by: xdono

Reviewed-by: chegar

Reviewed-by: darcy, weijun