Fix for IMyBlockGroup changes.

Note that stable as of this date has a game bug (that was fixed in the dev branch!) where disabled thrusters still contribute thrust.

If resuming cruise after a re-compile or world reload, the first "cruise stop" issued will be equivalent to "cruise reset" -- it will reset all thrusters.

This prevents restoring the thrusters to a disabled state (because they were previously shut off upon attaining the desired speed).

This is a safety/convenience fix since most people probably wouldn't have "cruise reset" on their toolbar.

• Changed the behavior of "cruise stop". After stopping, it will restore thrusters to their state before the first cruise command used since the last time you stopped. Thruster enable/disable state as well as override settings are preserved.
  
  Note that this state is not currently saved in block storage -- so reloading the world or re-compiling the prog block will make it forget any saved settings.
  
  If there are no saved settings, "cruise stop" does nothing (aside from stopping the script).
  
  
• Added command "cruise reset" which is basically the old "cruise stop" command. It will stop the script and it will re-enable all thrusters. You can still specify which type of thrusters to touch, i.e. "cruise stop ia" to only touch ions & atmo thrusters.

• Measure velocity based on frames rather than real time. Makes things smoother when sim speed is erratic.
  
• Add bias factors for asymmetric thruster configs. It should be <1.0 if it favors the thrusters for the forward, left, up directions. >1.0 for the others. Experimental, leaving everything at 1.0 is the original behavior.

Saves the last cruise control command issued in block storage (i.e. semi-permanent, survives world reloads) and re-issues the command when initializing for the first time.

Prevents crazy things from happening if you happen to save while cruise control is active and then later re-load that save.

Fix bug where certain grid pivot orientations would cause the current speed to be always read as 0 (causing the ship to always accelerate...)

Now you can cruise in any direction. Simply specify the direction after the speed, for example:

Valid direction keywords: forward or forwards, backward or backwards or reverse, left, right, up, down

If you don't specify a direction, it will cruise forward by default.

You can also cruise using only a type or types of thrusters.

Simply specify one or more letters after the direction: "i" for ion thrusters, "a" for atmospheric thrusters, "h" for hydrogen thrusters. If you use this feature, you MUST specify the direction as well. For example:

The first cruises forwards using only ion and atmospheric thrusters. The 2nd cruises upwards using only hydrogen thrusters. Note that the script will not touch the type of thrusters you don't specify -- so for best effect, you must turn off unused thrusters OR turn off dampeners.

Note: Because I know of no scripting API to determine the type of thruster (aside from using its definition display name), the cruise functions probably only work when the client is set to English. Sorry!

One last thing. "cruise stop" will also take thruster type letters. Without any thruster type, it will enable and reset all thrusters regardless of type. But the following:

Will enable and reset only ion and atmospheric thrusters. Hydrogen thrusters will remain untouched.

The speed "dead zone" has been extracted into an easy-to-edit constant near the top of the script named CRUISE_CONTROL_DEAD_ZONE. By default, it is .02 (or 2%), which means that once it is within 2% of the target speed, it will shut off forward and reverse thrusters.

If there is a block group named CruiseControlGroup defined, restrict actions only to thrusters of that group.

Workarounds for broken generics in 01.102.