Move run_ssh class variable into skip decorators

We shouldn't do a getattr on CONF in the class definition. It will cause
import errors if there isn't a config file. Just use
CONF.compute.run_ssh in the skip decorator.

Change-Id: I948ac411d4af9844f2c69fb91f7c0fdc3aaf7fe4
add trace_requests option to debug section

this supports the use case that David Kranz has in tracing
specific tests for test development. Because this is expected to
be development only, and not used in a general case, we don't do
all the md5 niceties of the previous code.

Change-Id: Ia9c7a7d10456d0583f8897111b958050c8e95ed7
Merge "add trace_requests option to debug section"
Merge commit 'refs/changes/65/81565/4' of git://gold.eng.hq.xensource.com/git/github/openstack/tempest into tmpbranch