Support for Auto evalution time in Charts

Currently the dtd for a jrxml only supports the following evalutation times:

Now, Report, Page, Column Group, Band

Textfield also allows Auto, which allows calculating totals at the end of the report (useful for percentages) - however to generate a chart with the same values would presumably also require the ability to specify Auto for Chart evaluation time.

The alternative is, as was the case in 1.2, to precalculate the total and return it as part of the dataset - which is not ideal.