Java 8 compile fix

Compilation with Java 8 had failed:
reference to Parameter is ambiguous.
both class java.lang.reflect.Parameter in java.lang.reflect
and interface com.wordnik.swagger.models.parameters.Parameter in com.wordnik.swagger.models.parameters match
Fix ScalaModelTest and compile error for Reader.java
Add support for parsing allOf from a spec file. Only writing was supported.
merge upstream changes
Treat additional allOf refs in Json as interfaces. Turn unit tests back on.
updated property access
added tests
Merge branch 'develop_2.0' of github.com:swagger-api/swagger-core into develop_2.0
Merge pull request #734 from martoe/java8

Java 8 compile fix
Merge pull request #779 from mbarbanson/develop_2.0_interfaces

Develop 2.0 interfaces
Failing unittests (Windows) ignored
Implemented vendor-specific fields at Operation and Parameter level
Make response headers available to the code generator
Use an own version number for this fork
Error handling improved