Fix LazyModule.__dir__ on python 2.7

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Add support for strings in _glibc_type()

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Add support for unions in _glibc_type()

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Improve utility of size mismatch assertion

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Change style of type annotation

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Add types/functions related to epoll(7)

This patch adds untested bindings for:
    epoll_create()
    epoll_create1()
    epoll_wait()
    epoll_ctl()
    EPOLL_CTL_ADD
    EPOLL_CTL_DEL
    EPOLL_CTL_MOD
    EPOLLIN
    EPOLLOUT
    EPOLLRDHUP
    EPOLLPRI
    EPOLLERR
    EPOLLHUP
    EPOLLET
    EPOLLONESHOT
    struct epoll_event

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