Ticks on lines with margin < 0

[alfredwassermann]

The property "margin" allows to have small margin inside of the canvas. This is ignored by ticks- Example:

var board = JXG.JSXGraph.initBoard('jxgbox', {axis:false,
        boundingbox: [-10,10,10,-10], keepaspectratio:true, ignoreLabels: false});

var xax = board.create('axis', [[0, 0], [1, 0]], {
            withLabel: true, 
            name:'x axis', 
            label:{
                offset: [30, 10], 
                position: 'lft'
            }, 
            margin: -50
        });

[alfredwassermann]

It may be a good idea to introduce a separate property "margin" for ticks.