update bundled Lua to version 5.2.2

5.2.2 is a bug-fix release; everything should still work the same way.
Merge pull request #2230 from johnbartholomew/lua-522

Update bundled Lua to version 5.2.2
Update Changelog.txt
Update Changelog.txt
Show distance on mission screen, sort by distance.
ui:Label color support
Mission screen shows colorful distance and days left.