Hi Guix,

the attached patch adds the Intel TBB library.

There are a couple of things I'm not sure about:

- should the examples be included per default or should they go into a
  separate "doc" output together with the /doc directory?  Together they
  take up about 10MB.
- the version number is only given as "4.3 Update 2 Current version" on
  the download page.  I turned this into "4.3.2", but I'm not sure if
  this is really equivalent or if we should rather use the datestamp on
  the tarball (= "43_20141204")
- the second paragraph of the description sounds a little too much like
  advertisement; any suggestions on how to reword this, or can I just
  delete the second paragraph?

Best,
Ricardo