When C++ methods are not able to be overloaded in a derived class,
such as when they differ by just const, or the target language
parameters types are identical even when the C++ parameter types
are different, SWIG will ignore one of the overloaded methods with
a warning. A %ignore is required to explicitly ignore one of the
overloaded methods to avoid the warning message. Methods added
in the derived classes due to one of the %interface macros are now
similarly ignored/not added to the derived class.
The adding of additional methods into the parse tree is now more
robust and complete resulting in support for %feature and %rename
for the added methods.
Closes#1277