Added typehinting, support for importing schema and wsdls and required variables only part of constructor
Merge nuth/wsdl2phpgenerator commit  '8a157324043f53ea1798d8b07c4f75aa9406b670'

Includes:
- Load schemas from WSDL
- Only add required (non-billable) properties to constructor
- Improved enum handling
- Code style fixes.

Dependency on Spl was intentionally not added.
Fixed merge error
Merge branch 'load_xsds_constructor_only_required_args'