Moved code using csNeedsBorderPaint into Delphi 7 ifdef.

Didn't compile on Delphi 6.
Merge pull request #49 from Gitek/HtmlViewer11

Moved code using csNeedsBorderPaint into Delphi 7 ifdef.
Merge branch 'HtmlViewer11' of git://github.com/BerndGabriel/HtmlViewer into HtmlViewer11