Description of Problem:
Disk Druid dies on 'odd' "Fill maximum size of (MB):" entries. For example:
10495-19478. Any strange characters in the int will screw it up. = works
too. 
<useless_crap>
	Don't bother asking me why I put a - in there...Bad typing, maybe? Oh
well.
</useless_crap>

How Reproducible:
Quite.

Steps to Reproduce:
1. Partition w/disk druid
2. Have some free space
3. Select "Fill maximum size of (MB)" option, and put a 'number' containing
an odd character (I know that - and = work, not sure about others) in the
space.

Actual Results:
Anaconda crashes and generates a backtrace (will be attached)

Expected Results:
Anaconda printing out a nice little "What the hell are you thinking?" error
message.

Additional Information:
Dump attached.