- on a rainy sunday night, implented one of the most requested feature which...

- on a rainy sunday night, implented one of the most requested feature which was little work and should make a lot of users happy!
fixes #747
adding links on both sub tables for search engines and keywords linking directly to the search engine page for this keyword
added definition for the main search engines (approx 15) users can contribute more if they like; if a definition, eg. "search?q={k}" for Google is not found, then we simply link to the search engine homepage.

updated FAQ on how to add a search engine see http://piwik.org/faq/general/#faq_39
added tests to check that the search engine file is defined properly
- renamed queuefilter to queueFilter for consistency


git-svn-id: http://dev.piwik.org/svn/trunk@1158 59fd770c-687e-43c8-a1e3-f5a4ff64c105