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/dialogxml/scrollbar.h

@@ -28,7 +28,7 @@ public:
 	explicit cScrollbar(cDialog& parent);
 	void attachClickHandler(click_callback_t f) throw(xHandlerNotSupported);
 	void attachFocusHandler(focus_callback_t f) throw(xHandlerNotSupported);
-	bool triggerClickHandler(cDialog& me, std::string id, eKeyMod mods, location where);
+	bool triggerClickHandler(cDialog& me, std::string id, eKeyMod mods);
 	bool handleClick(location where);
 	void setFormat(eFormat prop, short val) throw(xUnsupportedProp);
 	short getFormat(eFormat prop) throw(xUnsupportedProp);