Improved the parachute targeted landing by:
1) controlling parachutes and cruising to deceleration burn / course correction at the same time
2) Improved the dynamic time step code for the reentry simulation.
3) Better modeled the game's parachute deployment drag curve
Added Target Argument of Periapsis as an Info Item
Merge branch 'dev' of https://github.com/MuMech/MechJeb2 into dev

Conflicts:
	MechJeb2/MechJebModuleLandingAutopilot.cs
	MechJeb2/MechJebModuleLandingPredictions.cs
	MechJeb2/ReentrySimulation.cs
Fixed a problem with the merge from the MuMech branch
Auto tune Tf for the Attitude Controler
Allow external module to provide the Terminal Velocity
Merge branch 'dev' of https://github.com/MuMech/MechJeb2 into dev
Debug to investigate the null mainbody error
Tune the Tf Auto Tune
* Added option to target VAB roof
* Tidied up the Landing Guidence prediction screen
* Added terrain height ASL to prediction and target locations on Landing Guidence screen
* Added parachute multiplier to Landing Guidence screen
* Seperated deceleration ASL and landing ASL concepts in the reentry simuation
* Added exception handling and improvide diagnostics
* Made simulation timestep variable
* Added handling for the game providing inconsistant terrain data
* Stopped autopilot from attempting course corrections once parachutes are deployed
* Added an experimential CoastDecentSpeedPolicy because previous once caused the simulation to hover and timeout.
Add ModuleControlSurface torque. I did not see they added it in .23
Disable Rendezvous AP if a target move outside the ship SoI
Merge remote-tracking branch 'cp/dev' into dev

Conflicts:
	MechJeb2/VesselState.cs
Merge pull request #1 from MuMech/dev

Merging lastest changes into codepoet development branch
Fixed a bug introduced in the recent landing update that caused TerrainAltitude to be called from the simulation thread. Now it is only called from the main thread, which seems to result in less bizzare things happening in the log, and no (less?) visual glitches in the terrain rendering
Merge pull request #273 from codepoetpbowden/dev

Fix for graphical glitches and bizzare behaviour on landing introduced in latest landing update
* Added time to land / exit atmosphere to the Landing screen
* Added parachute targeting information (quality and amount of data being used)
* Tidied up Landing screen
* Increase the amount of error added to error simulations to improve parachute targeting
* Increased the number of predictions used for parachute targeting to 40
* Changed landing gear to always lower at 1000m AGL regardless of the landing step
* Removed redundant code
* Changed to parachute targeting to discard non-correlating data, but always continue trying to build a good dataset
Merge pull request #274 from codepoetpbowden/dev

Improved parachute targeting; tidied and added more info to the landing screen.
Fix some .23 related NRE on decoupling/undocking
Merge branch 'dev' of https://github.com/MuMech/MechJeb2 into dev