Merge lastest 1

Lorenz,

Here is an attempt to sync the lastest libopencm3 into PX4. What I did was cloned the latest libopencm3 code into libopencm3/ and cloned your project into libopencm3-old and did the following:

$ cd libopencm3-old
$ git checkout -b merge-lastest-1
$ get fetch ../libopencm3
$ git reset --hard FETCH_HEAD
$ get push origin merge-lastest-1

I'm not sure this is correct, but the result of the two directories were identical according to meld. And when I look at the history of the result in libopencm3-old/ it looks the same as lbiopencm3/. See what you think.