say.c: Fix cents off-by-one due to floating point rounding.

say.c: Fix cents off-by-one due to floating point rounding.

Some of the money announcements can be off by one cent,
due to the use of floating point in the money calculations,
which is bad for obvious reasons.

This replaces floating point with simple string parsing
to ensure the cents value is converted accurately.

Resolves: #525