Merge pull request #715 from sappo/master

Problem: No consistent code format.
Revert "Problem: No consistent code format."
Merge pull request #716 from zeromq/revert-715-master

Revert "Problem: No consistent code format."
Problem: No consistent code formatting.

Solution: Use uncrustify code formatter.

Remarks:

* No automatic removal of braces for one line if statements that are
  in fact multiple-line macros as those will result in compile errors.
* Line break at 120 characters as this cannot be undone and 90 or 100
  caused a lot of weired breaks.