Code review comment for lp:~widelands-dev/widelands/bug-1395278-editor

Found only intended renamings or improvements,
Added some comments about minor things.

New for me are warnings like:
[ 44%] Building CXX object src/logic/CMakeFiles/logic.dir/map_objects/tribes/requirements.cc.o
.../bug-1395278-editor/src/logic/map_objects/tribes/requirements.cc:247:5: warning: format specifies type 'unsigned int' but the argument has underlying type 'uint8_t' (aka 'unsigned char') [-Wformat] TrainingAttribute::kHealth,

I think someone reenabled that clang warning.

Can be merged