Revert "Teach the build system about mod_dash"

This reverts commit b1a3892a5b..., because I found a more effective
way to wire in mod_dash, that is, I include it as a folder inside the
root directory, and I patch the system path accordingly.

To wire in mod_dash with the current diff, instead, I would need to
add a special case for the zipimport in utils_modules.py, which seems
to me less robust on the long run.
Teach the build system about mod_dash -- version 2

This time we just copy the content of the module into the
versiondir, like we do for the web pages.
add 0001.patch: include ROOTDIR in sys.path if needed

Py2exe configures the system path to include the zipfile only.

We ship the mod_dash as a folder outside of the zipfile, because
this kind of deployment fits better with utils_modules.py code.

Therefore we also need to patch the system path to include the
root directory, which contains the mod_dash.
Win32/setup.py.in: remember to compile the mod_dash folder