max bin slider is broken, but only for lines.

This is due to the commented out portion of bridgecharts.js in line 129.
Look at the area, it jitters. Therefore both are broken, just in
different ways.
area and line rendering are now consistent with eachother
getting close, dependent on xScale now though
split it out
in the middle of something
current status: lines get thicker when zooming
looks preeetty good. The -3 is important I think
looks good, exit transitions are broken now
simplified
removed useless comments
a bit weird, but working 95%