New version 2.7.1

Switch to version 2.7

Set new process-related fields to zero during conversion

Prepare for release 2.5

Various corrections.

Adapt man page for showing full process list for memory sorting

Implemented polling mode in case NETLINK refuses with error EINVAL.

Due to kernel bug 190711, the NETLINK interface gives EINVAL when
it is activated. Since atopacctd misses a trigger then to read
the process accounting records when processes in the system terminate,
a polling loop has to be used to verify the existance of new
process accounting records.

Minor bug-fixes.

Support systemV and systemd RPMs.

Correction of typo's in the man pages, including a wrong counter name

in the output of atop ('udpie' for UDP input errors).