Catkinised phidgets_drivers metapackage (take 2)

This is the same pull request as #5, only with the history somewhat cleaned
up. We haven't had time to test this on our hardware yet, so please wait
a little before merging this.

Some things which are a little confusing at the moment:
* actually, ccny-ros-pkg/fuerte, ccny-ros-pkg/groovy, ccny-ros-pkg/hydro and ccny-ros-pkg/master all have identical code, which is somewhat obscured by the mass of merge commits
* muhrix/groovy also has all of those commits, again a little hard to see because of another set of  merges

What I'd like to have in the end:
* ccny-ros-pkg/fuerte should point to the last commit before catkinization
* there should be a linear history of catkinization commits, starting
  with ccny-ros-pkg/fuerte
* ccny-ros-pkg/groovy and ccny-ros-pkg/hydro should point to the same
  commit, after the catkinization

What I've done in this pull request to do achieve that:
* rebased muhrix/groovy on top of ccny-ros-pkg/fuerte to get rid of
  redundant merge commits
* Squashed some commits that corrected mistakes in a previous commit into that commit (e.g. 4e196cf99d207b7375cda35176c678bdb51e7350), i.e. making it appear as if the offending file never *was* in the repo. This just makes the history more readable, the result is still the same.
* fixed the repository path in the README.md

What still needs to be done after merging:

    git checkout hydro
    git merge groovy
    git push