Merge pull request #103 from MOARdV/master

Add some null checks in MJRPM + change an error message
Compute closest approach to landed targets properly.

Previously, the target approach variables appeared as NaN, and
the orbital display freaked out and stopped showing anything.

To avoid this, first compute the correct approach time by emulating
the planet rotation, then create a circular pseudo orbit that passes
through the target at the correct time for other code to use.
Fix rendering of post-node orbits on the ScanSat screen.

The code should still use the current time as the base for planet
rotation compensation, instead of the node time. Otherwise nodes
and the subsequent orbit are shifted out of place proportional to
time until node.
Merge pull request #104 from angavrilov/master

Improve usability for landing at a specific location.

...Am I correct in thinking this closes #81 ?
Observe KERBIN_TIME introduced in 0.23.5

I think this should smoothly take care of all instances since we use
seconds everywhere else.

Fixes #107
Claw support everywhere.

This adds claws to targeting menu, undocking menu, camera support and
adds an ISCLAWREFERENCE variable.

I *think* I got everything, but it needs some testing research on what
kind of state strings do claws have and which states signify the claw is
undockable. See FIXMEs.
Removing deprecated variables.

It's really been long enough and I think with the release being nudged
by the appearance of 0.23.5, we could do with less things to support.
ISREMOTEREFERENCE variable

Makes more sense if we're allowing claw cameras.
ISONKERBINTIME

Might come in useful.
Support targeting asteroids in KSP 23.5