FW aileron trim won't work with equal deflections

[Bill-B]

When roll trim is ON, the check we do to make sure there is an aileron will fail if there are two ailerons with equal but opposite deflection. (Ex. -5 and +5)

FreeWake/Source/longtrim.cpp

Lines 122 to 130 in ba2bafc

	tempsum = 0;
	for (i = info.panel1[0]; i <= info.panel2[0]; i++) { //for all panels on wing 1
	tempsum = +panelPtr[i].deflect1;
	}
	if (tempsum == 0) {
	printf("No aileron defined on wing 1.\n You must define a deflection on at least one panel on wing 1. \n");
	scanf("%c", &answer);
	exit(1);
	}

Also unrelated but we can maybe decrease the allowed error on Cl for roll trim.