libdfp: Fix ChangeLog dates
PowerPC: quantized[32|64|128] refactor.

This patch fixes quantized32 by adding a check to see if the
adjusted coefficient will fit in _Decimal32.
It also refactor quantized[32|64|128] to avoid the include/macro mess
and using a more straight implementation.
libdfp: Inputs added to the quantized tests.

This patch adds inputs to test the overflow of quantized[32|64|128].