Explicitly declare void for all void parameter functions (#628)

Apparently in C, if you have `void test();`, it's completely okay to do
`test(2);`. The function will take in the argument, but just discard it
and throw it away. It's like a trash can, and a rude one at that. If you
declare it like `void test(void);`, this is prevented.

This is not a problem in C++ - doing `void test();` and `test(2);` is
guaranteed to result in a compile error (this also means that right now,
at least in all `.cpp` files, nobody is ever calling a void parameter
function with arguments and having their arguments be thrown away).
However, we may not be using C++ in the future, so I just want to lay
down the precedent that if a function takes in no arguments, you must
explicitly declare it as such.

I would've added `-Wstrict-prototypes`, but it produces an annoying
warning message saying it doesn't work in C++ mode if you're compiling
in C++ mode. So it can be added later.

desktop_version/src/Logic.cpp

@@ -10,7 +10,7 @@
 #include "Script.h"
 #include "UtilityClass.h"
 
-void titlelogic()
+void titlelogic(void)
 {
     //Misc
     //map.updatetowerglow(graphics.titlebg);
@@ -41,14 +41,14 @@ void titlelogic()
     }
 }
 
-void maplogic()
+void maplogic(void)
 {
     //Misc
     help.updateglow();
 }
 
 
-void gamecompletelogic()
+void gamecompletelogic(void)
 {
     //Misc
     map.updatetowerglow(graphics.titlebg);
@@ -81,7 +81,7 @@ void gamecompletelogic()
     }
 }
 
-void gamecompletelogic2()
+void gamecompletelogic2(void)
 {
     //Misc
     map.updatetowerglow(graphics.titlebg);
@@ -121,7 +121,7 @@ void gamecompletelogic2()
 }
 
 
-void gamelogic()
+void gamelogic(void)
 {
     //Misc
     if (map.towermode)