Fix for labeling bar graphs

This branch contains a fix for #11.

The bug is that we get a crash when attempting to label bar graphs:

<pre>
Uncaught exception: TypeError: Cannot convert 'v[x*(B||1)+s]' to object

Error thrown at line 7, column 3997 in <anonymous function: M.label>(y, S) in http://localhost:8000/media/js/g.bar-min.js:
    T=c.g.text(v[x*(B||1)+s].x,S?A+d-g/2:v[x*(B||1)+s].y-10,U).insertBefore(e[x*(B||1)+s]);
called from line 19, column 6 in <anonymous function>() in http://localhost:8000/blog/:
    chart.label(labels);
called from line 26, column 212 in <anonymous function: ready>() in http://localhost:8000/media/js/jquery-1.4.1.min.js:
    a.call(r,c);
called via Function.prototype.call() from line 33, column 9 in <anonymous function: L>() in http://localhost:8000/media/js/jquery-1.4.1.min.js:
    c.ready()
</pre>

The problem was simply that a set of variable assignments were misordered:
         multi = len;
         len = 0;

I've fixed both g.bar.js and g.bar-min.js