hgweb: make graph data suitable for template usage Previously, graph data has been encoded for processing done by JavaScript code run in the browser, employing simple structures with implicit member positions. This patch modifies the graph command to also produce data employing a dictionary-based structure suitable for use with the templating mechanism, thus permitting other ways of presenting repository graphs using that mechanism. In order to test these changes, the raw theme has been modified to include templates for graph nodes and edges. In a similar fashion, themes could employ technologies such as SVG that lend themselves to templating to produce the graph display. This patch makes use of a much simpler output representation than SVG in order to maintain clarity.