@sjaeckel integrated clang-format with formal coding style. Run his
script and commit changes.
There are pros and cons of this commit.
Mixed coding style is a "broken window". A good single style simplifies
reading and writing code.
On the other hand, this is a big change which will lead to conflicts.
XEP-0077 will not be implemented as part of libstrophe's API, but an
example is provided. The example shows how to use the "raw" connection
to register a user.
Closes#54.