Add creation of points layer and..

Addresses issues:
Issue 43 Now creates the points layer.
Issue 71 Numbers not being integers.  Testing using GB OS also broke here
with '**********' being the value, in which case set value = 0.
Fix typo in mapstyle.py.
Merge pull request #82 from EvansMike/master

I've added a points layer and some other minor fixes.  Hope these are useful.