#9 Auto shrink dihedral angle ranges

[jurgenfd]

The range on Omega angles should not be a full 360 because the info is in the detail. Shrink if restraint and actual values fall within narrower range.

(I see there are different preferences for ranges for the different psi, chi1 etc. I like that because that's how authors think. I'm noting it so I can do the same in Wattos.)