Initial staging for economics view improvements.
Added label indicating current system and selected system, also if there are no items in a trade category.
Colour adjustments
Merge branch 'master' of github.com:Dessimat0r/pioneer into econ-improv
It could probably use some optimization and I'm not sure about exact correctness of math used, but it should be immeasurably better than what we had before.
Planetary Temperature Fix for Multiple Stars

Temperature for planets in multiple systems should now be calculated correctly, or approximately correctly in all cases.
Possibility of Life Respects Stellar Lifetimes

If system couldn't have existed long enough for life to form (based on one of its stars being too massive), there will be none, if it has, life will be scaled accordingly to the time it could have had to develop.
Also removed explicit checks for star types - those cases are either handled automagically by mass check (hot, massive stars), or are no longer checked for (life around white and brown dwarfs is considered unlikely and requiring rather special circumstances to form but *NOT* impossible).
Fix for temperature overflows during system generation.

Everything normalized to Earth's values like a good little Earth chauvinist should.
Fixed temperature calculation for binary orbiting planets in quarternary systems.

Bug due to misinterpretation of (rare) orbital configuration, fixed by reordering of conditions checked.
Merge branch 'temperature_overflow_fix' into multiple_system_temperature_fix
Added (obvious) check to functions checking if body is coorbiting.
prevent saving the game if the player is already dead

for #3056, #2895
handle errors from Game.SaveGame when autosaving or saving from settings
add slot as third arg to Ship:AddEquip
Merge remote-tracking branch 'jpab/issue-3056'
fix -Wshadow warning in StarSystem.cpp
modify scan_enums so that it explicitly converts values to int in its data

This is necessary when generating tables for strongly typed enums
(that is, the 'enum class' syntax), because they don't have an implicit
conversion to int.
remove various unused methods and variables
remove ShipType::equipSlotCapacity array
update documentation comment for Lua Timer:CallEvery