Fail if given an unrecognised option.

I renamed UsageError to UsageMsg because it just logs, unlike
ArgumentError which exits the process with an appropriate error
code. Then replaced one case of UsageMsg with ArgumentError where we
should be failing hard.

Also inlined OptionsHelp so the usage an be seen in one place in the code.

Test: odrefresh --foo --compile
Change-Id: If01902ebe652c20949a454e64849e7d39c2b8748
1 file changed