Add possibility to not show the search box in a search page + install taxonomy page by default but not enabled

Initial patch

Todo : When #1305282: Search pages problems is committed the update should be updated to reflect the setting that the taxonomy page should not have a search box enabled.
Todo : Also the sensible default for the taxonomy page should not have the search box enabled

New patch after the commit of #1305282: Search pages problems
This one should apply cleanly and allow any search page to display/hide the search box by checking it in the advanced options + add this option to the update script or the install script.

More changes to make it more robust.

1) Added some variable check to the title
2) Added a check for the results (to ignore invalid paths)
3) Added the taxonomy page to the install process by default however it is not enabled

Todo in another issue would be the visibility of the search pages. It is not clear if a search page is enabled or disabled right now.

Code standards not 100% compliant after review.

Committed