Improved node render engine

What's new

• Improve page rendering #45
  • remove theme suggestions
  • use template blocks and only provide proper context
  • deprecate page layout elements
  • remove front-end libraries #43
• Admin: add m2m related fields on both ends:
  • page types / blocks
  • nodes / terms

All changes

• Integrate tests into django-ninecms repo #44
• Use Python path functions in image styles #48
• Fix #47 setup fails
• Use Travis and Coveralls #35

⚠️ Changes that require manual migration actions:

• Upgrade all templates
  • Block rendering has changed, add relevant include statements according to readme instructions.
  • Anywhere that image styles are used, pass the actual ImageFieldFile rather than a url #48