Merge branch 'develop' of git.mpimet.mpg.de:libmtime into develop

* 'develop' of git.mpimet.mpg.de:libmtime:
  [develop]  removed obsolete moduloTimedelta function. The functionality is covered by divideTimedelta, see the examples/modulo.c implementation.
  [develop]  Changed event groups to a list of POINTERs (this is necessary for the ocean's event manager).
  [develop]  Fixed datetimeToPosixString wrapper (fatal typo).