Fix bootchart2 never stopping on non-GUI operating systems with systemd.

This patch series fixes a regression introduced in 56a638a, where the systemd files were renamed to use the bootchart2 name, but their dependencies on each other were not updated (so bootchart2.service still referred to the now nonexistant bootchart-done.timer instead of bootchart2-done.timer.)

It also renames the .in files for the systemd service files to make the situation less confusing.