Android Studio build fixes 2of2 -- Fix dStrstr and other build errors
Torque's `strstr` variant wasn't standard library compliant and has been fixed for all platforms that Torque 2D compiles for and runs on. Was explicitly corrected for Android Studio because current compiler refuses to allow old/incorrect usages.
Fixed pointer comparison to integer error, another thing not allowed by current compiler.
Fixed `free` and `malloc` undeclared function warnings.
delegateSignal.h's `_SIGNAL_H_` header guard collided with Unix signal.h's header guard, changed to `_DELEGATESIGNAL_H_`.