Changes

Create hierarchical submodule for tosca models
 (commit: c2926d1)

Stop creating repositories left and right and instead inject it

Also properly separates different repository implementations from one another.
Additionally define the dependency graph through a submodule system.
 (commit: d734f7b)

Stop incorrect conversions between null, "null", and "" for properties
 (commit: 74563ae)

Fix serialization and deserialization issues

Notably corrects the derived_from reading for InterfaceTypes and includes DataTypes into serialzation
 (commit: 3429238)

Add support for keySchema and entrySchema in properties definitions for YAML
 (commit: a134b11)

Minor todos
 (commit: a1dcc77)

Extract ComplianceRuleChecker Tests into separate class

Also fix some minor bugs around Property Mapping
 (commit: adddbcb)

Fix unit PropertiesDefinition serialization
 (commit: 7bdd239)

Do value-bodging for Property Definition default values
 (commit: 494e0d5)

Minor fix

Signed-off-by: Michael Wurster <miwurster@googlemail.com>
 (commit: f7e3e7d)

Housekeeping: Imports, Domain-Class Prefixes and cleanup (#212)

 (commit: 283b4f6)