A slight fix for SDL2 for windows compiling.

You shouldn't have to put SDL2 in the root include directory. If your
machine is setup like that, then your machine is setup wrong.
fix sign warnings in mutation.cpp
fix sing warnings in live_view.cpp
fix sign warning in overmapbuffer.cpp and player_activites.cpp
fix sign warning in input.cpp and inventory_ui.cpp
fix some sign warnings in game.cpp and astyle
Fix %% typo when reading books
Strip trailing spaces from map screen per issue #6478
Stripped spaces per issue #6478. For real this time.
Merge style, warning, and translation cleanups.