Add support to max-height, max-width, min-height and min-width

[Dev1lDragon]

in function initScrollbar add:

 ...
             state.el2.style.height = '100%';
            state.el2.style.maxHeight = 'inherit';
            state.el2.style.minHeight = 'inherit';
 ...
                     state.el2.style.width = '100%';
                    state.el2.style.maxWidth = 'inherit';
                    state.el2.style.minWidth = 'inherit';

and in destroyScrollbar add:

                state.el2.style.height = '';
                state.el2.style.maxHeight = '';
                state.el2.style.minHeight = 'inherit';   
                state.el2.style.width = '';
                state.el2.style.maxWidth = '';
                state.el2.style.minWidth = 'inherit';

[DominikSerafin]

Related: #52