Merge PR #27481 into master

* refs/pull/27481/head:
	qa: add a method to test if a file can be created
	qa: add wrappers for vstart's run() with check_status as False
	qa: add a method to create an empty file with any user
	qa: add stdin parameter to run_shell
	qa: command to be ran as a different user should be a single string
	qa: looks for quotes in Python shell and get rid of them
	qa: move checks on command arguments to a different method
	qa: accept args as strings
	qa: add a method to run given command as root user
	qa: add a method to run a command as a different user
	qa: allow keeping sudo in command arguments
	qa: make execution abortion optional for command ran through run_shell()

Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>