Improves packaging of wikis, some usage of HTML head tags, exporting of static content, and internationalized text in some areas.

Changelog:

 - fixed #9264: new slideShow.swf uploaded in extras/ukplayer (United Knowledge/Arjan Widlak)
 - fixed #9428: added Keywords to Asset::get when no property is named
 - fixed #9410: Wrong help text
 - fixed #9492: Problem in passing form variables to Macro SQL inside a snippet
 - fixed #9404: Head tags for admin user with admin mode off
 - fixed #9507: Navigation: relDepth is calculated with starting point, instead of the first displayed page
 - fixed #9511: Subcategories displayed incorrectly (Henry Tang, Long Term Results B.v.)
 - fixed #4137: Calendar Search no longer puts head tags in body
 - fixed: Paginator generates bad markup for next page links
 - fixed: Exporting to static files can leak large amounts of memory
 - fixed: HTTP Proxy doesn't serve new content to visitors
 - fixed: WebGUI doesn't handle UTF8 encoding on JSON consistently
 - fixed: Asset Manager can generate URLs that are too long