View source for CC Search integration

[[CcSearch]] at http://search.creativecommons.org (also accessible via [[Firefox_and_CC_Search|Firefox]]) simply "frames" CC-enabled search engines.

To accomplish this, candidate search engines need to support the following query components in GET URLs:
* keyword
* restriction to only CC-licensed or PD results
** restriction to only results that permit commercial use
** restriction to only results that permit derivative works

Typically, these will map to four URLs, each with an arbitary keyword parameter.

=Example implementations=

==Yahoo! Web Search==

* Any CC
** http://search.yahoo.com/search?cc=1&p=KEYWORDS
* Permits commercial use
** http://search.yahoo.com/search?cc=1&ccs=c&p=KEYWORDS
* Permits derivative works
** http://search.yahoo.com/search?cc=1&ccs=e&p=KEYWORDS
* Permits commercial and derivative use
** http://search.yahoo.com/search?cc=1&ccs=c&ccs=e&p=KEYWORDS