Run unused functions reported by cppcheck
This change removes a few (but not all) unused functions.
Some unused helper functions were not removed due to their complexity and potential of future use.
Blacklisted characters are replaced by '_' in the path. The display name is stored in world.mt, and duplicate file names are resolved by adding an incrementing suffix (_1, _2, _3, etc).
The game minetest.conf flags directly overwrote the global minetest.conf default values, resulting in unwanted erased mapgen flags.
* Fix set_mapgen_setting
Use "append" method to construct the various game paths
instead of wasteful string concatenation. Additionally, use a
temporary to extract and reuse a result of a few common
subexpressions to further reduce the overhead.
Reserve space for the list of games in findWorldSubgame. The
performance gain is pretty much negligible but this change
also gets rid of a performance warning by CLANG TIDY.
This patch will make distinguishable mods in modpacks possible in the future
`nil` checks are required to provide backwards-compatibility for fresh configured worlds
