Large number and analog menu item fixes, IoAbstraction 1.6

Large number improvements and bug fixes - now negative values are configurable, works properly with integers up to 9dp.
Analog WholeAndFraction bug fixes around small negative numbers
Move to IoAbstraction 1.6, giving much greater task management capabilities when running on RTOS (see TaskmanagerIO)

If you run into any issues with this, please report them here and move back to the previous version of this and IoAbstraction.