Python function annotations removed from -py3 option.

Python function annotations containing C/C++ types are no longer
generated when using the -py3 option. Function annotations support
has been moved to a feature to provide finer grained control.
It can be turned on globally by adding:

  %feature("python:annotations", "c");

or by using the command line argument:

  -features python:annotations=c

The implementation is designed to be expandable to support different
annotations implementations. Future implementations could implement
something like the following for generating pure Python types:

  %feature("python:annotations", "python");

or typing module types to conform to PEP-484:

  %feature("python:annotations", "typing");

Closes #1561
Issue #735

Examples/test-suite/python/Makefile.in

@@ -48,6 +48,7 @@ CPP_TEST_CASES += \
 	li_std_wstring_inherit \
 	primitive_types \
 	python_abstractbase \
+	python_annotations_c \
 	python_append \
 	python_builtin \
 	python_destructor_exception \

Examples/test-suite/python/python_annotations_c_runme.py

@@ -0,0 +1,27 @@
+import sys
+
+if sys.version_info[0:2] >= (3, 2):
+    from python_annotations_c import *
+
+    anno = MakeShort.__annotations__
+    if anno != {'x': 'int', 'return': 'Space::Template< short >'}:
+        raise RuntimeError("annotations mismatch: {}".format(anno))
+
+    anno = global_ints.__annotations__
+    if anno != {'ri': 'int &', 't': 'TemplateShort', 'return': 'int *'}:
+        raise RuntimeError("annotations mismatch: {}".format(anno))
+
+    ts = MakeShort(10)
+
+    anno = MakeShort.__annotations__
+    if anno != {'x': 'int', 'return': 'Space::Template< short >'}:
+        raise RuntimeError("annotations mismatch: {}".format(anno))
+
+    anno = ts.mymethod.__annotations__
+    if anno != {'arg2': 'int', 'tt': 'TemplateShort', 'return': 'void'}:
+        raise RuntimeError("annotations mismatch: {}".format(anno))
+
+    # No annotations
+    anno = no_annotations.__annotations__
+    if anno != {}:
+        raise RuntimeError("annotations mismatch: {}".format(anno))