Merge pull request #15 from xhaakon/master

Fix parsing of /proc/${pid}/maps with deleted files
Don't remove core_pattern on system shutdown

Some executables can still crash after core_pattern is removed. Those
cores were dumped into /var/cache/core-dumps, ignored by crash-reporter,
not being deleted and slowly consuming available space. In order to
prevent it, we keep the pattern set until the full system halt.