Silence sign comparison warnings by iterating with a size_t instead of an int.  Also silence some unused parameter warnings.
Fix misc warnings in advanced_inv.cpp
Fix misc warnings in addiction.cpp
Fix misc warnings in animation_tiles.cpp
fix Wswitch in computer
fix Wsign warnings. input.h clean now.
fix Wsign warnings. npc.h cleaned
Fix misc warnings in artifact.cpp
fix of Wsign. computer.cpp cleaned.
fix of Wsign-compare in uistate.h and bionics.cpp
fix Wsign-compare in dependency_tree.cpp
Fix Wswitch in colors.cpp
fix Wsign-compare in melee.cpp
Fix Wsign-compare in item.cpp and item_group.cpp
Merge branch 'fix-sign-compare-warnngs-2' of https://github.com/kevingranade/Cataclysm-DDA into kevingranade-fix-sign-compare-warnngs-2
Merge a pile of warning fixes.

Conflicts:
	src/input.h
	src/item_group.cpp
	src/overmap.h
Merge branch 'master' of https://github.com/CleverRaven/Cataclysm-DDA into towel