Clone/fake form tweaks

[HebaruSan]

I had a lot of UI suggestions for KSP-CKAN#2665, so rather than going through them one by one in comments, here they are in easily mergeable code form.

• Move the radio buttons into the section headers
• Enable/disable clone/fake controls based on the radio buttons
• All fields aligned at right with labels at left
• Removed pseudo ghost text
• Replace instance selection button with dropdown (reverse sort by version)
• Path selection buttons shrunken and placed after their fields
• Added a Cancel button
• Renamed OK button to Create
• Pressing Esc will cancel out of the form
• Pressing Enter will attempt to proceed
• Moved those buttons to very bottom by themselves
• Moved progress bar to left of the buttons
• Removed the FormCompatibility stuff since it isn't needed
• Catch all exceptions since leaving the input path blank wasn't showing an error

[DasSkelett]

Nice!
Two smaller issues I see on Windows:
The radio buttons are a bit higher than on Linux, so they are not centered with the group box line.
Also the two select buttons are a bit smaller, but that's not that life threatening.

[HebaruSan]

Looks like that's about 5px off, so I split the difference so it'll be 2-3px off in different directions on Mono vs Windows (and the Select buttons are slightly larger now):

[DasSkelett]

Looks good now!

Thanks a lot!