Add Mod10 to Custom Data Type Manipulator for Modbus Interface

Please add support for SquareD Mod10 custom datatype to the Modbus Interface. Schneider Electric uses a custom datatype that uses four 16 bit registers. Each register represents an integer. Each integer is then multiplied by a factor and all results are added together. Currently the only way I know how to read this is to create a PI modbus point for each register value, then create a calculated PI point to perform the math to add them together. All the values are in consecutive registers, so they could be read with one call to the device, if there were a built in calculation to combine them. As it is now it takes four calls to the device to get the one value. It also takes 5 PI Tags when it could only take one. Register List for PM800 Series Power Meters MOD10 Each register represents a value from 0-9999, these register values are then appended to one another (number of registers is dependent on size of the Mod10 value) to form a data value (first register is least significant). Mod10_Value = (Register4 * 1000000000000) + (Register3 * 100000000) + (Register2 * 10000) + (Register1)