CSS Selector inconsistency

[lukerollans]

There's an inconsistency present when passing in selectors. IE, activeClass can be passed in unqualified, but containerSelector needs to be fully qualified.

EG, this will not work

$('.post .sidebar.lower').pin({
    padding: {
        top: 10,
        bottom: 10
    },
    activeClass: 'pinned',
    containerSelector: 'pin-parent'
});

But this does

$('.post .sidebar.lower').pin({
    padding: {
        top: 10,
        bottom: 10
    },
    activeClass: 'pinned',
    containerSelector: '.pin-parent'
});

It could be argued that this is semantically correct, given the difference between the option names.. EG "Class" as opposed to "Selector".

Will open a PR for this issue if no-one else gets to it first