omniNotify

When you type
make DESTDIR=/some/sandbox install

All files must be installed under the root '/some/sandbox/$prefix'
In the current version of omniNotify branch omniNotify2_develop some files
are made in the '/$prefix' instead.
This patch fixes that.
The patch includes changes of some paths in the
omniNotify/mk/beforeauto.mk.in
The changes are taken from omni/mk/beforeauto.mk.in

I needed this to write proper ebuild script to install omniNotify under
gentoo.