task: by rsevero: Fixed information on README.txt about which libraries need extra downloads to work.

  types and including links to each charting library home and reference pages on help pages.

bug #803654 by seanr, rsevero: Fixed (?) by attaching a behavior to the page that recalls the chart drawing function.

feature #831962 by rsevero: Patch applied and included definition of Bluff's special parameter "transpose" in Bluff's Advanced Help page.

task by rsevero: Applied the right fix for NOTICEs on pie charts by Open Flash: only they have series as an array of objects and only they don't need min and max values for y axis. Removed min and max values search and attribution for pie charts.

task by rsevero: Fixed NOTICEs generated when looking for min and max values for pie charts. These values aren't even useful for pie charts but it might affect other types of graphs so I didn't disabled this search for pie graphs.

task by rsevero: Implemented option parameters on charts_graphs_test() so it can be used also for Advanced Help examples.