new splash screen

why:

- the current splash-screen has no referring to official images on - https://en.bitcoin.it/wiki/Promotional_graphics
- the current splash screen only exists in a low res jpg
- current splash screen looks dark and "hackish"
- new splash screen should generate positive, "trust-emotions".
- new splash screen gives the user infos about the running client.
- new splash screen can handle long messages (in a lot of - languages the text is cropped in current release)

- new size (x2) 400x312

- contains textual information about the client
- textinfos are dynamicly written to the pixmap

when -testnet is switch on, the splashscreen will show the bitcoin logo in testnet-color (as well as a text [testnet])

example: https://dl.dropbox.com/u/7383846/new_bitcoin_splash.png

src/qt/splashscreen.h

@@ -0,0 +1,16 @@
+#ifndef SPLASHSCREEN_H
+#define SPLASHSCREEN_H
+
+#include <QSplashScreen>
+
+/** class for the splashscreen with information of the running client
+ */
+class SplashScreen : public QSplashScreen
+{
+    Q_OBJECT
+
+public:
+    explicit SplashScreen(const QPixmap &pixmap = QPixmap(), Qt::WindowFlags f = 0);
+};
+
+#endif // SPLASHSCREEN_H