Add support for setting charset

Fix phonetics. End index must be larger than begin index.

Update test files. All .xml files now start with 1, i.e. no more sheet.xml (without digit). Digits now also decimal based, not hexadecimal.

Shadows on cell text are not supported. Remove it from the test. Shadows are supported only on textboxes and shapes.

When setting cell value to RichText, don't use SetEnumerable.

Fix XLColor equals method (#25) ...

* Use ToArgb() to compare equality of colors, in order to return TRUE when comparing RGB(FF,FF,FF) to White.
http://stackoverflow.com/questions/8146453/system-drawing-color-equality-operator-doesnt-treat-0xffffffff-as-color-white

* Add test for named color vs RGB

* Update bespoke unit tests files to remove duplicate font styles.

* Set substringo of rich text to Garamond font, instead of Broadway. Broadway probably isn't installed on the AppVeyor server. Garamond is a much more common pre-installed font.

* Disable different font to see if it affects the AppVeyor build.

* Use Courier font for rich text. Hopefully this one is installed on AppVeyor.

Resaved the xls file in excel

Project hierarchy cleanup