Eliminates the eval() step in the csv module resulting in better
security, more clarity, and a little speed.
The idea is to make successive attempts to coerce the string to
a python type:
int(s), long(s), float(s), etc.
As a by-product, eliminates a bare 'except' statement.
due to using a single module-level namespace where multiple namespaces
were used before.
There *really* need to be tests for the sniffer stuff. This could
have been avoided.
Skip, please review, and add sniffer tests!