#77 new shortcuts are lowercased but modifying existing shortcuts are case-sensitive

The following sequence of commands causes an error:

!shortcut+ sd-governance-MRs #snowdrift
!set shortcuts.sd-governance-MRs.prefix governance!

with !get shortcuts we see that the shortcut was created as sd-governance-mrs.

Solution: !set should convert the first argument to lower case, as !shortcut+ does.

I changed stuff in the shortcut code. Can you please test again and let me know if it works in a more expected way now?

Seems to work now.