Implement version information storage and retrieval for the bootrom and the osimage.

Use perl to create the version information (thereby re-creating the perl dependency and adding an svn dependency) but fall back in case of missing perl or svn

armsrc/apps.h

@@ -112,5 +112,6 @@ void LED(int led, int ms);
 void LEDsoff();
 int BUTTON_CLICKED(int ms);
 int BUTTON_HELD(int ms);
+void FormatVersionInformation(char *dst, int len, const char *prefix, void *version_information);
 
 #endif