Upgrades: Changes based on speed-review by Cyp.
Fix copy/paste error found by forum user Duha.
Upgrades: Fix bug that would upgrade buildings not affected.
Upgrades: Fix bug whereby values would be set in one script and read wrong in another.
Upgrades: Add rudimentary documentation of Stats and Upgrades globals
Upgrades: Add back functionality whereby resistance circuit research would give
droids increased resistance as well.
Upgrades: Add missing RearmPoints handler in rules.js