Reviewed by Darin

    Reviewed by Darin

	Fix for <rdar://problem/3854383> REGRESSION(166-168) input fields show black background when background color is set to transparent
	and a workaround for displaying transparent backgrounds for textareas.

        * kwq/KWQLineEdit.mm: (QLineEdit::setPalette): If the background color is transparent (we check the alpha value) then we set the background to white
        * kwq/KWQTextEdit.mm: (QTextEdit::setPalette): If the background color is transparent then we don't draw the background
        * kwq/KWQTextArea.mm: (-[KWQTextArea setDrawsBackground:]): added setDrawsBackground function which calls setDrawsBackground on the super class,
          on the contentView, and on the textView.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@7944 268f45cc-cd09-0410-ab3c-d52691b4dbfc