add rsyslog entrypoint

[riuvshin]

What does this PR do?

add entrypoint to rsyslog image where we kill pid file if it exist before start rsyslog, that may happen on force restart container and rsyslog wount be able to start.

What issues does this PR fix or reference?

fixes #1940

Changelog

add rsyslog entrypoint

[dmytro-ndp]

Works properly in CentOS 7.2 with docker 1.12.6.

Before:

[vagrant@dev ~]$ sudo docker ps -a
76cc9de37e3c        codenvy/rsyslog:nightly      "rsyslogd -n"            3 days ago          Restarting (1) 53 seconds ago   0.0.0.0:5140->514/tcp                                codenvy_rsyslog_1

[vagrant@dev ~]$ sudo docker logs codenvy_rsyslog_1
rsyslogd: pidfile '/var/run/rsyslogd.pid' and pid 1 already exist.
If you want to run multiple instances of rsyslog, you need to specify
different pid files for them (-i option).
rsyslogd: run failed with error -3000 (see rsyslog.h or try http://www.rsyslog.com/e/3000 to learn what that number means)

After this fix rsyslog container was restarted correctly without errors:

f012ef111e99        codenvy/rsyslog:nightly   "/entrypoint.sh"         10 minutes ago      Up 14 seconds       0.0.0.0:5140->514/tcp                                codenvy_rsyslog_1

[benoitf]

if you can bump the date of the copyright to 2017

[riuvshin]

sure