'allow' floats for motor speed and dots/commas in floats

[ArendJan]

techniek studio instructor came with these issues:

• allow floats for motor speeds, at least in blockly, maybe a conversion in the set motor speed input (robot.setspeed(..., int(12.1))
• dots vs commas in blockly floats as Dutch students use a comma by default instead of the 'required' dot.