Remove ability to get several boundary ops at the same time from a few of the schemes While it can be handy the code for the getBoundaryOp methods get needlessly cluttered

function y = rickerWavelet(x, x0, A)
    y = (1-2*pi^2*A^2*(x-x0).^2).*exp(-pi^2*A^2*(x-x0).^2);
end