Use "compact" arguments form for the function if "default" typemap is defined
for any of its arguments to allow omitting this argument when calling it from
Python.
Closes#377.
Accept not only manifest pointer types (such as e.g. "void *") but also types
that are typedefs for pointer types when checking whether C++ value of 0 must
be represented as 0 or None in Python.
Closes#365, #376.
Default values are no longer generated as Python code by default.
They must be explicitly turned on using the "python:defaultargs" feature.
Closes#294Closes#296
The problems in these two issues when "python:defaultargs" is turned
on still need to be fixed and should be addressed in separate patches.
The important thing is the default code generation is now fixed.
Enum values are just (integer) constants in Python and so can be used as the
function default values just as well as literal numbers, account for this when
checking whether function parameters can be represented in Python.
Also rename is_primitive_defaultargs() to is_representable_as_pyargs() to
describe better what this function does.
