Combining Area & Line plots. Text alignment of axis labels. Supporting demo

Attached is a patch file that contains the following:

- Feature to support mixed Area & Line plots on the same chart (something we needed)
- Feature to align axis label text to either Left, Centre or Right (something we needed)
- Demo of the Area & Line chart LineArea07 with a sample of some of our data and the padding included

There is a TODO as, with 2.4.1, the handling of axis labels changed and now we need the ability to set the format for X and Y axis independently.