Review postscriptStemSnapH and postscriptStemSnapV values

[rimas-kudelis]

It seems there are too many of them and some may not be needed.

E.g. for postscriptStemSnapH (typical horizontal stem widths), by looking at typical text characters of Jonova Regular, I couldn't find any stems with width 246 or 202, and even finding 142 was a stretch.

Useful reading material:

• https://glyphsapp.com/learn/hinting-postscript-autohinting
• https://blog.typekit.com/2012/04/03/robothon-2012-talks/