Improvements to SwatHtmlTag: 	- make $content property private 	- add setContent() method with optional mime type param
Improvements to SwatHtmlTag:
	- make $content property private
	- add setContent() method with optional mime type param

The mime type now defaults text/plain instead of text/xml. This is a safer default as it is obvious when XHTML is output literally, but not so obvious when a few special characters are not escaped.
	- 


svn commit r2977

silverorange/swat,silverorange/swat