Profile editor: Add proper format to white spaces.

The generic highlighter already provided a method for this.
This method was then lifted to the base syntax highlighter
and it is now used by the profile highlighter.

Reviewed-by: Roberto Raggi
Task-number: QTCREATORBUG-2448

src/plugins/texteditor/syntaxhighlighter.h

@@ -89,6 +89,8 @@ protected:
     void setFormat(int start, int count, const QFont &font);
     QTextCharFormat format(int pos) const;
 
+    void applyFormatToSpaces(const QString &text, const QTextCharFormat &format);
+
     int previousBlockState() const;
     int currentBlockState() const;
     void setCurrentBlockState(int newState);