Add weak dependency of atop to atopacctd for starting...

... I do not think atopacctd should be stopped when atop is stopped as
an interactive atop may still be running.
script provided facility names must not start with '$':

Provides: boot_facility_1 [boot_facility_2...]

defines boot facilities provided by this init script such that when
the script is run with the start argument, the specified boot facilities
will be deemed present and hence other init scripts which require those
boot facilities must be started at a later stage. Normally you should use
the script name as boot facility (without .sh if the file name has such an
ending) but one can in the exceptional case also use the name of the
service(s) that the script replaces. Boot facilities provided by scripts
must not start with '$'. (Virtual facility names listed below are defined
outside the init.d scripts.) Facility names should be unique within the
distribution, to avoid 'duplicate provides' errors when a package is
installed.

https://wiki.debian.org/LSBInitScripts