- remove the version numbers
- simplify the texts
The date and version number will be put there for releases when maketgz
runs the updatemanpages.pl script.
Closes#11029
- they are mostly pointless in all major jurisdictions
- many big corporations and projects already don't use them
- saves us from pointless churn
- git keeps history for us
- the year range is kept in COPYING
checksrc is updated to allow non-year using copyright statements
Closes#10205
