How to make two small changes to a contourplot produced in lattice

问题

I would like to make two cosmetic changes to a contourplot using the lattice function. These are

1. to expand the size of the panel titles;
2. add a title to the legend and key section, and shrink the colorkey object to fit this.

A graphic showing what I mean is below, as on this occasion it will likely be more informative than the code.

Solutions to either or both problems much appreciated.

来源：https://stackoverflow.com/questions/25400734/how-to-make-two-small-changes-to-a-contourplot-produced-in-lattice