WebSearch: add "em" parameter

• The "em" parameter is passed through the url. It is a sequence of characters separated by commas. Depending on the following values, different parts of the page are shown: Common to search and collection page: B - Body H - Header F - Footer S - Search box L - See also box, with links to other search engines (for external collections) Specific to search page: K - Basket A - Alerts I - Search info O - Results overview Specific to collection page: P - All portalboxes Pte - Title epilog portalbox Ptp - Title prolog portalbox Pnp - Narrow by coll prolog portalbox Pne - Narrow by coll epilog portalbox Plt - Left top portalbox Prt - Right top portalbox So, for example, to show the body, the footer, the title epilog portalbox and the left top portalbox, the "em" parameter should look like: em=B,F,Pte,Plt The values can appear in any order
• Change webcoll cached files structure (now uses cPickle)