API: Track options and version

If options are not present in .api.json file
(e.g. old PVP build), use an empty dict.
If a message is used in CSIT, check its options.
Tolerate vat_help, but print warning for others.
This aims to discover in-progress and obsolete APIs.

If .api.json version is not detected, or starts with "0.",
add a "version" item to options, so they get reported.

Change-Id: Ic5a9423157728a58f7ad306c7bd9eaef3bd92488
Signed-off-by: Vratko Polak <vrpolak@cisco.com>