* Chart Dynamic Title and Special Font Properties
Fix#3797. Excel allows a Chart Title to be a formula, albeit a very rigidly limited one. It can only be a reference to a single cell, and the worksheet name must be specified, and the column and row must be absolute. Methods are added to Chart/Title to accommodate this (and styling for it). This will be handled for input/output for Xlsx, and for output for Html.
The sample file which was submitted with this issue demonstrated that something else was missing. When setting the font for a chart title in Excel, you can specify all-caps or small-caps, options not available for most cell formatting. These are now added.
The sample file also fell into the category of spreadsheets which lose one or more charts when converted to Html. I have redone the "extend rows and charts" logic in Html Writer. It is now clearer (I hope) and more efficient, and hopefully this problem will not arise again.
* Scrutinizer 50/50
One false positive, one correct "unused parameter".