This is a preview for a new feature of hledger-web.
It adds serving balance reports from hledger-web.

So far there remain some issues:

• I generate HTML with Lucid and then convert to Blaze. Instead I will add a new spreadsheet export backend Write.Html.Blaze. We can later discuss whether we want to keep Lucid, at all.
• Balance reports are currently integrated in the defaultLayout, which means there is always the sidebar. Do we want that? Of course, the user can hide the sidebar with s key. However, I found the query field useful in conjunction with the balance reports.
• Links to the balance report are only integrated in the Journal view for now. I could also move them to the query field component. Or above the Journal link in the sidebar.
• In a further commit I want to add radio buttons for the Layout type, maybe also the format type (TXT, CSV, FODS, HTML), maybe turn the period selection into a radio button, as well.
• The sidebar link to Journal does not maintain the current query. In the past I did it this way in order to have quick way out of restrictions posed by queries. However, all other accounts in the sidebar in the query and the hyperlinks behind dates in transactions in the Register page also maintain the query. Since I currently have the links to balance reports on the Journal page it would be nice if the top Journal link in the sidebar would also contain the query.