add jackson JSON parser
fix call to chefnode
Merge branch 'develop' into jersey_jackson

* develop:
  doc restyling
  doc restyling
fix: remove null fields
fix unit test
fix: don't write empty list in json
Merge pull request #96 from alberts-tid/bug/CLAUDIA-4225

add logs to delete node methods
fix, line size to 120chars
Merge pull request #97 from jesuspg/jersey_jackson

Jersey jackson
add sonar plugin and reconfigure cobertura plugin
sonar test