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

doc/assets-attribution.txt

@@ -44,11 +44,6 @@ Designer: Everaldo (Everaldo Coelho)
 License: GNU/GPL 
 Site: http://findicons.com/icon/17102/reload?id=17102
 
-Image: src/qt/res/images/splash2.jpg (Wallet image)
-Designer: Crobbo (forum)
-Site: https://bitcointalk.org/index.php?topic=32273.0
-License: Public domain
-
 Icon: src/qt/res/icons/debugwindow.png
 Designer: Vignoni David
 Site: http://www.oxygen-icons.org/
@@ -57,6 +52,7 @@ License: Oxygen icon theme is dual licensed. You may copy it under the Creative
 Icon: src/qt/res/icons/bitcoin.icns, src/qt/res/src/bitcoin.svg,
       src/qt/res/src/bitcoin.ico, src/qt/res/src/bitcoin.png,
       src/qt/res/src/bitcoin_testnet.png, docs/bitcoin_logo_doxygen.png,
-      src/qt/res/icons/toolbar.png, src/qt/res/icons/toolbar_testnet.png
+      src/qt/res/icons/toolbar.png, src/qt/res/icons/toolbar_testnet.png,
+      src/qt/res/images/splash.png, src/qt/res/images/splash_testnet.png
 Designer: Jonas Schnelli (based on the original bitcoin logo from Bitboy)
 License: MIT