Sanity check digit seperation on parsed string

[sjoerdsimons]

It's quite easy to confuse the exponent seperator and digit seperation especially when working with different currencies. Luckily the digit seperation pattern is different from the exponent size in most currencies, which means that sanity checking the digit seperation should catch most of those mistakes.

Signed-off-by: Sjoerd Simons sjoerd@luon.net

[varunsrin]

this is great, thank you for writing this and adding tests.