Macro argmin::make_terminate

macro_rules! make_terminate {
    ($condition:expr, $reason:path;) => { ... };
    ($condition:expr, $reason:path ; $($x: expr, $y:path;)*) => { ... };
    ($self:ident, $($x: expr, $y:path;)*) => { ... };
}

This macro generates the terminate function for every solver which implements ArgminSolver.