#235 Adjustable taskbar width

[Wilco]

This patch adds two options to make the taskbar width adjustable. "TaskBarWidthPercentage" sets the width of the taskbar in percentages between 0 and 100. "TaskBarJustify" aligns the taskbar to the left, right or center. This is a small patch which adds some nice eyecandy in my opinion.

Examples
85% width, justified center: https://s1.file1.info/uiCKHfqh
50% width, justified right, taskbar at top: https://s1.file1.info/KYFsoe2h

[Wilco]

Taskbar flexible width patch

[Frank W McCormick]

Looks great. I'd use it! Now if Ice only supported transparency :)