Space Shuttle Vessel v1.16

Adds CRT mission timers, and improved ascent guidance.

Fixes the Preview mode in Mission Editor, and adds Xenon Lights to STS-8.

Added missing dependency from previous release.

This release features a rework of the Mission Editor, a sizable update to the manual, the addition of manual on/off control to the Xenon Lights, and a better light beam.

It adds the Payload Bay preview feature, so users checkout the payload bay while setting up payloads in Mission Editor. Also new is the IUS propellant load calculator, making up much easier to setup the IUS so it delivers a payload to a target orbit. Smaller changes include improved launch pad meshes, a fix for the scenario start time, and small corrections and improvements.