message: Update to version 2.0.6
diff: // These need to be macros, as version.cpp's and bitcoin-qt.rc's voodoo requires it
  #define CLIENT_VERSION_MAJOR 2
  #define CLIENT_VERSION_MINOR 0
  -#define CLIENT_VERSION_REVISION 5
  +#define CLIENT_VERSION_REVISION 6
  #define CLIENT_VERSION_BUILD 0
  // Converts the parameter X to a string after macro replacement on X has been performed.
  