test of type and safety draft
Merge branch 'master' into typeandsafety
Merge branch 'master' into typeandsafety
Merge branch 'master' into typeandsafety
strange bug, some clean up, inheritance hierarchy will be resolved in conversion
minor changes to sort logic
Merge branch 'master' into typeandsafety

* master:
  remove requirements from setup.py
  Fix: Small fix in sofa export
  Fix: Lung examples does not work #14
  small bug fixes in app and nsofa
  add run-msml-operator, one program to rule all operators from the command line
  restore old requirements.txt
  rework frontend, untested
  msml python-side is installable
  Fix: sofanew.py now adds material definition to the correct sofa-node.
  bug fixes in annotation (xml.py)
  first analytics
  begin analytics modul
New concept of Exporter based on Visitor Pattern

- not tested
add some viewer from the vtk python examples
vtk api has changed between 6 and 5.

Version 6.0.x is current default in fedora.
fix #25

xml.xsd is missing
move msml.xsd to msml package so it can be found
add check command for validating msm.xml only
relaxed xsd validation, bug in lxml
more "event" in visitor (for workflow, variables,...)
fixed types for simulation step
a factory for better python support

* see test_factory.py
* added msml writer from msml-gui
* bug fixes in attribute parsing
add travis.yml
Update .travis.yml
Update .travis.yml