turned the graphs into SVGs

Even though it is a pity to get rid of the wonderful hack that created the PNG graphs
[get graph png from xively with pink colored line, invert the picture to get green on black, crop to remove the "powered by xively" tag]
I still think that scalable SVG graphs are the way to go, especially considering the weird, almost idiotic labelling of the y-axis on the generated PNG graphs.

So I basically removed all the PHP cruft that fetched and edited the graphs and replaced it with:
* d3.js
* rickshaw
* moment.js
* xively.js

these fetch the datapoints for:
* power consumption
* payback points
* temperature inside and outside
* bank account balance

and create nice rickshaw graphs in the position where they belong (replacing the contents of divs of course)