Embedded xrc dialogs

I just committed a change to cvs, enabling to load the xrc resources
from binary instead of file. When defining EMBED_XRC, the dialogs
generated in ui/common/xrcDialogs.cpp are used, and the ui/common
directory isn't needed for execution any more. Currently, the macro is
defined for Release versions in win32, and undefined in Debug versions.
We could do the same for Linux.

To compile the xrc sources into the xrcDialogs.cpp, the script
ui/common/embed-xrc is used.

Unfortunately, I didn't succeed in making the xrcDialogs.cpp under msdev
automatically, dependent on ui/common/*.xrc; should be no problem in
Makefile though (if wxrc is present, this should be checked in configure).

Under Win32, I used an enhanced version of wxrc which is able to
evaluate wildcard filenames. The current version will not do this, but a
patch is already posted to wxWindows.

Regards,
Andreas