Changes to build RPMs (master branch), fixes issue #36

This is the pull request for the master branch. I cherry picked my changes from the release-1.3.x branch into master. Let me know if you had something else in mind.

I updated the shared lib and package version numbers to 1.4.0 under the assumption that 1.4.0 would be the next release branched off of master. If the next release ends up being 2.0.0, you can always change the number later.

I've also removed dashel's dependencies from EXTRA_LIBS because they shouldn't be necessary if you are using a shared dashel lib that dynamically links to its dependencies as provided by my recent decent dashel pull request (https://github.com/aseba-community/dashel/pull/4).