Suppress unused argument warnings in unavoidable cases

It would be nice if Eclipse were smart enough to ignore unused
argument warnings on @UiHandler and @Option methods, but alas it does
not. Suppressing these is ugly, but based on all the cleanup in the
previous commit, the benefit outweighs the cost.

Change-Id: I743917787ffb53be034eee3af2c525652fc18cb0
30 files changed