Simultaneous serial and internal control of throttle and axes

[phardy]

Adds configuration options to throttle, translation and rotation controls allowing various combinations of control by serial device and by the usual KSP internal mechanism. These controls are now configured by ints rather than bools, with the following possible settings:

• KSPSerial Control is disabled. Identical to the old boolean off option.
• KSPSerial Control is enabled and total. Identical to the old boolean on option.
• Control can be set by both KSPSerial and KSP internal, but priority is given to the internal setting. KSPSerial will only overwrite a control if internal is setting it to 0.
• As above, but priority is given to KSPSerial over KSP internal. The internal setting will only be used if KSPSerial is setting the control to 0.

[zitron-git]

OK version 0.17 should be now up to date, can you have a look at this again? I don't think it will require any major changes. I'll merge this once you can confirm this is working with 0.17 and we can release as 0.17.1. Thanks.