Lego WeDo extension improvements

[ericrosenbaum]

• Change tilt axis labels "up" and "down" to "front" and "back"
• Change the input to the "set light color" block to a color picker
• All menus should be non-droppable (i.e. for menus to select motor, motor direction, or tilt direction, do not allow a reporter to be dropped onto the input)
• Decrease the extra latency that we added to command blocks (this reduces risk of an OS crash due to a flood of commands, but was too conservative I think)

[cpseager]

Please also consider 'this way/that way/other way' (rather than 'this way/that way/reverse') for motor direction. Children seem to expect reverse to be the 'backwards' direction (as in forwards/backwards), not to swap direction.

[ntlrsk]

Also to consider for WeDo Scratch 3.0 update:

• adding "shake" for tilt sensor input (as in WeDo software)
• rename "play note" to "play tone" (or something else to distinguish from other Scratch music blocks)
• add block to "change light color by" (not essential)