Four refactorings:

	1) Relieve Bitbus from range checking.
	2) Let SPI calculate nr of needed bytes i.s.o. hardcoding.
	3) Let SPI only check communication lines in realmode.
	4) Attempt to write too large value in register is not fatal anymore.
Fix: remove debug output.
Rename name of DigitalOuts.
Create ability to lock other (so both) pages of DoubleBuffer.

	Needed when a parameter needs to be set in both pages.
Provide ability to set value of parameter in both pages. 

	When setting parameter from terminal only one page is updated. In 
	general, parameter needs to be effectuated in both pages.
Add functionality to retrieve size of allocated memory.
Check whether sufficient memory is available for Parameter creation.
Expose bitbus registers externally i.s.o. BitBus itself.
Instantiate Motor model.