Switch return type of _execute/_draw/_delete to be bool by default instead of BOOL

It's not completely consistent, but it seems like the majority used `bool`, and only a handful used `BOOL`. So I switched all of them to `bool` except for 13 TUs that stopped matching when changed like this.

src/d/actor/d_a_obj_hat.cpp

@@ -32,17 +32,17 @@ void daObjHat_c::createInit() {
 }
 
 /* 000006AC-000006DC       .text _delete__10daObjHat_cFv */
-BOOL daObjHat_c::_delete() {
+bool daObjHat_c::_delete() {
     /* Nonmatching */
 }
 
 /* 000006DC-0000073C       .text _draw__10daObjHat_cFv */
-BOOL daObjHat_c::_draw() {
+bool daObjHat_c::_draw() {
     /* Nonmatching */
 }
 
 /* 0000073C-00000884       .text _execute__10daObjHat_cFv */
-BOOL daObjHat_c::_execute() {
+bool daObjHat_c::_execute() {
     /* Nonmatching */
 }