refs #335, style sheet fixes / improvements and support methods

style sheets:
* style sheets with background textures
* scroll area / toolbox style sheet fix
* floating dock widgets
* kept 1st version of stylesheets in backup directory
* removed maininfoarea stylesheet, no longer needed with fixed style sheet

code
* central paintEvent method to enable style sheets in derived widgets
* detect frameless windows, dynamic properties

src/blackgui/components/logcomponent.cpp

@@ -9,6 +9,9 @@
 
 #include "logcomponent.h"
 #include "ui_logcomponent.h"
+#include "../stylesheetutility.h"
+
+using namespace BlackGui;
 
 namespace BlackGui
 {