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_machine.cpp

@@ -8,7 +8,7 @@
 #include "d/d_procname.h"
 
 /* 00000078-000000A8       .text _delete__11daMachine_cFv */
-BOOL daMachine_c::_delete() {
+bool daMachine_c::_delete() {
     /* Nonmatching */
 }
 
@@ -63,7 +63,7 @@ void daMachine_c::set_mtx() {
 }
 
 /* 0000100C-000010F8       .text _execute__11daMachine_cFv */
-BOOL daMachine_c::_execute() {
+bool daMachine_c::_execute() {
     /* Nonmatching */
 }
 
@@ -88,7 +88,7 @@ void daMachine_c::set_at() {
 }
 
 /* 000014D4-0000154C       .text _draw__11daMachine_cFv */
-BOOL daMachine_c::_draw() {
+bool daMachine_c::_draw() {
     /* Nonmatching */
 }