Updated sysvinit scripts

[Jorilx]

Created new sysvinit scripts by using the systemd unit files as guide.

Since every unit file follows the same template, I've written a service-template and a gen.sh to allow for the automatic generation of all the scripts.

Tested on Devuan 1.0 "Jessie" See #1125

[codecov[bot]]

Codecov Report

Merging #1126 into develop will increase coverage by 0.1%. The diff coverage is n/a.

@@            Coverage Diff            @@
##           develop   #1126     +/-   ##
=========================================
+ Coverage     84.9%   85.1%   +0.1%     
=========================================
  Files          102     102             
  Lines        17767   17767             
=========================================
+ Hits         15091   15126     +35     
+ Misses        2676    2641     -35