Discovered in #321. The number of argument for pa_rtpoll_run have
been changed since 6.0.
>=6.0 : int pa_rtpoll_run(pa_rtpoll *f);
<6.0 : int pa_rtpoll_run(pa_rtpoll *f, bool wait);
Check pulseaudio version by PA_CHECK_VERSION macro introduced since
pulseaudio 0.9.16. In case PA_CHECK_VERSION is not defined,
pa_rtpoll_run takes 2 arguments.
That can cause unexpected behavior, especially with third party tools.
The ignored files will be lost if the source tree is re-imported to
another git repository, unless special care is taken.
Whitelist all non-generated makefiles.
To whitelist instfiles/pam.d/xrdp-sesman, add path to all generated
executables listed in the top-level .gitignore, sort .gitignore
alphabetically.
Add mkinstalldir, it's used by Automake on some systems.