IMPALA-755: Fix shell hanging due to escaped quotes

Commands with escaped single quotes would cause
the shell to enter an infinite loop while trying
to parse the command due to shlex not escaping single
quotes correctly. Once that change was implemented,
shlex would now ignore escaped single and double quotes
outside of closed quotes, so there needed to be a check for
that as well.

ALSO, implemented testing of commands in interactive mode.
Needed this to test these inputs, as command line input
cannot span multiple lines.

Change-Id: Id67368944eeb9a73061bc3e90bd6cda73c9d9f64
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3408
Reviewed-by: Abdullah Yousufi <abdullah.yousufi@cloudera.com>
Tested-by: jenkins