proposal: numeric scale functions

Hi,

Dealing with "numeric"s right now in cases where it's really important 
that the scale is correct is quite painful.  For example, if I want to 
accept a EUR amount as an input, I often want to reject values such as 
'21.413', but I'd be fine with e.g. '21.410000'.  My suggestion is to 
add two functions: one to return the number of decimal places in a 
numeric, and another one to remove non-significant decimal places. 
These two functions are useful on their own, and when combined allow you 
to look at the number of significant decimal places in a numeric.

Any thoughts, objections?


.m