Rework weapon scheme handling in frontend and fix a couple of bugs There were many oddities in weapon scheme editing which are fixed now: * When you left the weapon scheme editor, everything flashed briefly * When you leaft the weapon scheme editr, the weapon scheme selection always reverted to Default. Very annoying * Clicking on New or Copy now instantly creates and save the new weapons set

void fpcrtl_halt(int num) {
    __coverity_panic__();
}

int fpcrtl_abs(int num) {
    return num >= 0 ? num : -num;
}