Nuke as many warnings as possible, and several globals as well

- Warnings completely suppressed for the included TinyXML and gzstream libraries
- Parentheses warnings are now errors, since there were several that looked like bugs
- Ditto for dangling else warnings

Some of these warnings were actually bugs:
- Town wandering monsters would have never spawned, because the code to do so was accidentally nested within a check for overall_mode == MODE_OUTDOORS
---> boe.monster.cpp, lines 105-137
- Monster's behaviour with respect to elemental fields did not correctly depend on their immunities (this is the same precedence issue Sylae messed up fixing in the Windows code)
---> boe.monsters.cpp, lines 345-359
- Display of damage blocked by armour appeared to be incorrect (needs verification)
---> boe.newgraph.cpp, line 1079
- Three-choice dialogs probably weren't dealing with unusual button types correctly, though that's a minor point since they aren't expected to use such buttons

osx/boe.text.h

@@ -41,7 +41,6 @@ void restore_mode();
 void through_sending();
 RECT coord_to_rect(short i,short j);
 void make_cursor_sword() ;
-std::string get_str(std::string list, short j);
 short calc_day();
 bool day_reached(unsigned char which_day, unsigned char which_event);
 void Draw_Some_Item (sf::Texture& src_gworld, RECT src_rect, sf::RenderTarget& targ_gworld, location target, char masked, short main_win);