Description of problem:
When you run spacewalk-clone-by-date without specifying starting date, it tracebacks with error which is not helpful to the user.


Version-Release number of selected component (if applicable):
spacewalk-utils-1.7.15-37.el6sat.noarch
(same issue on Sat541 and in current SWnightly)


How reproducible:
always


Steps to Reproduce:
1. # spacewalk-clone-by-date -u <user> -p <nimda> -s $( hostname ) -l <some_channel> <new_channel>


Actual results:
# spacewalk-clone-by-date -u <user> -p <nimda> -s $( hostname ) -l <some_channel> <new_channel>
Traceback (most recent call last):
  File "/usr/bin/spacewalk-clone-by-date", line 209, in <module>
    sys.exit(abs(main() or 0))
  File "/usr/bin/spacewalk-clone-by-date", line 198, in main
    args = parse_args();
  File "/usr/bin/spacewalk-clone-by-date", line 166, in parse_args
    options.to_date = parse_time(options.to_date)
  File "/usr/bin/spacewalk-clone-by-date", line 179, in parse_time
    if re.match('[0-9]{4}-[0-9]{2}-[0-9]{2}',time_str):
  File "/usr/lib64/python2.7/re.py", line 137, in match
    return _compile(pattern, flags).match(string)
TypeError: expected string or buffer


Expected results:
Error saying I do not have specified "--to_date".