This change adds two features for dealing with flags:
- requiring flags be provided as a group (or not at all)
- requiring flags be mutually exclusive of each other
By utilizing the flag annotations we can mark which flag groups
a flag is a part of and during the parsing process we track which
ones we have seen or not.
A flag may be a part of multiple groups. The list of flags and the
type of group (required together or exclusive) make it a unique group.
Signed-off-by: John Schnake <jschnake@vmware.com>
