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
Exit() is a wrapper for exit() by default, but SetExitHandler() allows
specifying a function to call instead.
This means that failures within DOH (e.g. Malloc() failing due to lack
of memory) will now perform cleanup such as removing output files.
This commit also cleans up exit statuses so SWIG should now reliably
exit with status 0 if the run was successful and status 1 if there was
an error (or a warning and -Werror was in effect).
Previously in some situations SWIG would try to exit with the status set
to the number of errors encountered, but that's problematic - for
example if there were 256 errors this would result in exit status 0 on
most platforms. Also some error statuses have special meanings e.g.
those defined by <sysexits.h>.
Also SWIG/Javascript tried to exit with status -1 in a few places (which
typically results in exit status 255).
