Update flot to a development version

This updates flot to version 0c2f6e3, which should be shortly before the
release of 0.8.2.  This is required for the tickrotor extension
(allowing rotated public body names on the x-axis).
Rotate labels on the x-axis by 90 degrees

This commit adds the tickrotor extension to Flot, which allows
rotated labels for public bodies.  This extension is licensed
under either MPL 1.1, GPL 2.0 or LGPL 2.1.
Only include minimal information about public bodies in JSON

Previously, the JSON included all the columns from the public
body table, which was unnecessary and included the public body's
email address.  Instead, just include the name and URL of the
public body.
Make bars in public body statistics charts clickable

Now if you click on the bar representing statistics for a
particular public body, it will take you to that public
body's page.

In addition, the bars are highlighted when you hover over
them.
Increase the number of public bodies per graph to 10

Now that there are rotated names on the x axis we shouldn't need
to worry about them overlapping, which was the reason for limiting
the number to 8 in the first place.
Refactor to avoid repeating .each_with_index.map
Add a tooltip to each bar of the public body stats graphs

Since the rotated public body names on the x-axis may be difficult to
read, it's helpful to have them in a tooltip as well.
Work around a bug in yui-compressor

jquery.flot.axislabels.js fails to minify with yui-compressor due to a
bug in it relating to delete being a keyword - we can work around this
by using the ['delete'] syntax instead.
Add (and use) minified versions of the Flot Javascript
Merge remote-tracking branch 'origin/stats-graphs-improvements' into rails-3-develop
Merge remote-tracking branch 'origin/rails-3-develop' into rails-3-develop
More general ignoring of config files.