V3.1.20 released

Hi all,

I have just uploaded V3.1.20 to www.sheetcam.com. This release has the following changes:

Added: os library to Lua macros. This mainly adds some useful date functions.
Changed: Spindle direction to thread direction in tapping process
Changed: help call to try to prevent hanging on some machines.

Could anyone having problems with the help file give this version a go.