Fix warnings by removing or suppressing warnings for:

o Unused variables and parameters
o Redundant inheritance, null chackes, and casts
o Hidden variables
o Deprecation
o Use of raw types

Review by: rjrjr, scottb



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@6468 8db76d5a-ed1c-0410-87a9-c151d255dfc7