Build with Tycho 0.20.

Tycho 0.20 is a bit old now but it's a good step towards using latest Tycho validating that nothing breaks with this version.
Merge pull request #135 from akurtakov/development

Build with Tycho 0.20.
Merge remote-tracking branch 'origin/development' into new_preferences
Updating build to use luna and not juno release.