Added the ability to display a custom header file above the area lists in the...

Added the ability to display a custom header file above the area lists in the area choosers.  Added the configuration options areaChooserHdrFilenameBase and areaChooserHdrMaxLines to specify the filename (without the extension) and maximum number of lines from the header file to use.  These are still beta versions, but these should be ready for an official release soon.