Fixes a lot of issues found by a code review done by Barry Warsaw. Those include: - Wrong signature for getters - Various memory leaks - Various optimizations - More consistent return values - Proper exception handling Signed-off-by: Stéphane Graber <stgraber@ubuntu.com> Reported-by: Barry Warsaw <barry@ubuntu.com> Acked-by: Barry Warsaw <barry@ubuntu.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>