Proper Mountain Movement & Exploitation Mod

This mod enables mountain exploitation by cities (a fairly straightforward change) and movement over mountains, but only for select unit types . Rather than permitting all units to travel over mountains, only the following units types are allowed to traverse the peaks: Civilian Units (Settlers, Builders, GreatPersonIndividuals, Naturalists, Religious Units); Recon Units (Scouts, Rangers); and, Helicopters, Observation Balloons and non-mechanized Support Units. The current version of the code finally resolves the issue where GreatPersonIndividuals were unable to move over mountains despite being explicitly permitted to do so in the code. Further instructions on customization are contained in the SQL file. Because of the way the movement system is designed in Civ 6, as long as a unit that can traverse the mountains has its full movement points, it can climb the peaks on the same turn (no matter whether its base movement points are 5 or 1). Accordingly, future plans for this mod include introducing a chance for the unit attempting to move over mountains to fail to move onto the mountain plot or to be pushed back (simulating a failure to cross a mountain range). This will be accomplished with LUA code. Another idea is to set up Projects that would allow a city that complete them to increase mountain yields. making mountains an even more valuable terrain over time.