[ipgen] Insert per-ip DO NOT EDIT comment

[matutem]

Description

Pass specific per-IP gen_comment parameter to ipgen and insert it when expanding each .tpl file.
Files that are simply copied should also get this comment inserted after the copyright notice, or after any number of lines of consecutive comments starting with the first line.
Make a special case for .core files since they must start with CAPI=2 and their comments start with '#'.

[pamaury]

Sounds like a good idea, in the multitop_dev branch I already added a couple of comments for generated files but you are right that this should also apply to ipgen and non-templated files.