ucommon: postpone copyright checker

[Peter Colberg]

Hi Jonas,

I would like to upload a new version of ucommon that fixes the FTBFS
with GCC 7 (#853397). I noticed that you revived copyright_hints from
the CDBS packging, which causes lintian to fail due to the FIXMEs.

I am certain that you put significant effort into the CDBS copyright
checker, and I would like to make use of it in the future. However, I
would prefer if the copyright checker were available independently of
CDBS and, more importantly, if it were integrated into the package
build process for automatic checking (maybe as part of lintian?).

Unfortunately I currently do not have the time to work on such an
integration. Would you be fine if we postpone the three commits
related to the copyright checker for now?

I preserved your changes in a personal branch js/copyright-check, and
I pushed the proposed upload to pcolberg/gcc-7. Please let me know
whether you are fine with the latter.

Regards,
Peter