Integer Overflow Checks

I disabled integer overflow checks in Weather Message 3.6 Beta 8.  I don't recall seeing an integer overflow in the programs.  This change will reduce the cpu consumption for all programs to some degree.

With integer overflow checks enabled, the internal routines would check to see if an integer overflow occurred for each math operation on an integer.  That is simply not necessary in Weather Message.  There are lots of loops that use integers in Weather Message.  Checking for an overflow in those well behaved loops is not necessary.