bump version to 1.7.2, change  xtext / xtend from 2.4.3 to 2.5.0
adaptions to xtext 2.5.0 - but maven build not yet working
xtext for DSL is back to 2.4.3
Merge branch 'develop-1.7.1' into develop-1.7.2
compile with Xtext 2.5.0
new feature: parent class ref in meta data
bugfixing
MANIFEST update????
allow to select tenant column creation in joined tables