Test generator hooks

Fixed issue where merging existing source files caused extra new line in existing code.

Added logic to load a project vendor/autroload.php if it exists.
Prevents errors when existing code uses third part libraries.

Added support for unit test generators.
Need to document and put an example in src/test-drivers.
Very basic information is in src/test-drivers/template.yaml.

Assume nullable type hint

Setting a method return type to an interface or class will cause the return type hint to be prefixed with "?", indicating the method may return null.
The doctrine entity builder will prefix the repository name with the entity namespace when the repository name is a bare class name.

Bug fix

Fixed ThridPartyClassBuilder::isClass() was returning false, preventing a subclass from extending the third party class.

Bug fix

Fixed bug in multi-line method prototype generator.

3rd Party Interfaces and Classes

Added support for 3rd party party interfaces and classes.
Use stereotypes "3rd-part-interface" for interfaces, "3rd-party-class" for classes.
Improved support for PHP types.
Use stereotypes "php-interface" for interfaces, "php-type" for classes.

Initial release

Fix importing constants and attributes/properties from existing source code.
Prevent trait methods from being imported in to using classes and traits when merging existing source code.