Mapstraction plugin: use minified sources for OpenLayers

Mapstraction plugin: use minified sources for OpenLayers

The default full build of OpenLayers.js is 943kb as of 2.10; this gzips down to a couple hundred kb
but is still rather nasty, plus loading it off a remote host could slow things down.

Using a local copy let us cut down the size significantly by discarding unused features, and further
minification with yui-compressor shaves a bit more off. Cuts down to about 1/5 the size of the
original.

Also threw in a bundled & minified copy of the Mapstraction classes plus our usermap.js,
which covers the common case of using the default OpenLayers provider. This cuts out three
additional script loads, two of which weren't getting launched until after the mxn.js main
file got loaded.