API securecall

Calls the specified function without propagating taint to the caller.
 ... = securecall(func or functionName, ...)
 ... = securecallfunction(func, ...)
==Arguments==
:;func: - A direct reference of the function to be called, or for securecall a string name of a function to be resolved through a global lookup.
:;...:Additional arguments to supply to the function.
==Returns==
:;...:The return values of the called function.
==Details==
* If securecall is called from a secure execution path, the execution path will remain secure when securecall returns, even if the called function is tainted, or accesses tainted variables.
* Errors that occur within the called function are not propagated to the caller; if an error occurs, securecall triggers the , and then returns control to the caller with no return values.
* For securecallfunction, no attempt is made to perform a global lookup based on the supplied function argument.
==Patch changes==