Make setup.py executable

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Add support for epollfd + glibc extensions

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Add the pyglibc._subreaper module

This patch adds a pythonic interface to the
prctl(PR_{GET,SET}_CHILD_SUBREAPER) interface.

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>