setting cache-control headers for map server

[Anand Chitipothu]

Chinmay/Deepak,

I profiled the loading time of the web pages and found the loading
speed can be improved by doing the following.

* set ows_http_max_age in mapserv config file to allow the client to
cache the map images.
I think we can safely set that value to 3600 (1 hour).
http://www.mapserver.org/ogc/wms_server.html

* Most of the time is spent in getting the OpenLayers.js file. Couple
of things can be done to improve this.
* set appropriate Expires/Cache-Control tag
* use gzip/deflate encoding. This will reduce the amount
transferred to one third. (see mod_deflate for Apache)

The same can be done for electionspot html files too. I'll see how to do that.

Anand