Problem: man7 (project overview) differs from man1/man3 (dev docs)
Problem: man7 (project overview) differs from man1/man3 (dev docs)

Solution: always generate and deliver the overview text for man7 page, avoiding conflict with possible class/main names (use different extensions). Also warn if the older *.txt filename exists, so maintainer might recommit it as *.adoc.

zeromq/zproject,paddor/zproject,paddor/zproject,taotetek/zproject,taotetek/zproject,zeromq/zproject,paddor/zproject,zeromq/zproject,taotetek/zproject