Added: Recursive downloads to lists

Little green button to recursively add attachments to user's downloads "cart" is implemented for composer and corpora list templates. The button is also added for search results (pieces, movements, corpora, composers).
Added: Mass-Download button for searches

User may now add all the results on a page of a query results to his downloads cart en-masse (only took a whole day to figure out where I went wrong...). TODO: If a whole lot of items are selected, this button would go ahead and insert everything. May want to have a dynamic warning alerting the user.
Fixed: Minor issues in templates

Comments with html coding are now not escaped; clearer separation of tags added