Add basic html rich text support
Add merge format API
Improve html rich text support

If contains only one text fragment with format, then it should be plain
text. And the format should be considered as Cell format
Code refactoring: rename one internal variable only
XlsxWidget example: Remove un-needed xlsx-private
Add load function for ContentTypes
Code refactoring: Remove magic things for ContentTypes
Code refactoring: Improve picture support

Don't lost picture information when edit existing .xlsx files
Update version to 0.3.0
Deprecate the old insertImage member of QXlsx::Document

We don't support offset / scale of image any more
Introduce new class OOXmlFile
Add basic graphicFrame support

First step for chart support
Code refactoring: Clean up
Add very basic chart support
Try add very basic barChart support.
Code refactoring of Chart part
Fix [-Wreorder] warning under clang
Add basic support for Bar3D and Pie3D
Code refactoring: Add more basic chart support
Merge branch 'master' into dev

Conflicts:
	src/xlsx/xlsxworksheet.cpp