Option to add timer label or image

Similar to other plugins, like system load monitor, adding a label or image next to the timer bar would be beneficial to know what the bar is.

For the image, the same hourglass image used in the properties/option dialog would be fine, while for the label, the user should be able to modify what it says.

Likely the options dialog should get a checkbox labelled 'show icon or label' and below that is two radio buttons to either select icon or label options.