WebSearch: first release of hosted collections

• Initial implemetation of hosted collections. Improvements are still needed.

• Fixed a bug that permitted a father and its child collections to be searched at the same time producing duplicate results.

• Added the remove funcionality of an already selected collection at the drop down menu of the search box.

• New generic Invenio-based external collection engine class. Supports XML-based fetching and parsing, jump to record.

• Adaptation of the webcoll deamon to support hosted collections.

• New Check external collections feature of the WebSearch admin.

• New function to get the contents of urls.

• New function to get an external collection's engine class.

WebSearch: get_coll_real_descendants extension

• extended the get_coll_real_descendants function to accept the type of relationship and whether to also retrieve the hosted collections on not as parameters