The `help` command was behaving a bit funky. This patch re-orders the
code a bit so that the `help` command will be parsed at the very
beginning before running other commands and checks.
It also allows to get help without downloading/checking schemas and
without requiring auth credentials (previously required by the schema
operations).
Change-Id: Ib7b10d4d80f15e6b75bb8644d7d916bef09413d6
Closes-bug: #1490457
5026774bd1