Verify that the username length is smaller than MAXLOGNAME when asked to verify a passwd file (pwd_mkdb -C).
Verify that the username length is smaller than MAXLOGNAME when
asked to verify a passwd file (pwd_mkdb -C).

Entries with oversized usernames are still permitted when building
the passwd database.

When entries are >= MAXLOGNAME in length, they are correctly stored
in passwd, pwd.db and spwd.db but are only correctly retrieved by
getpwent*() and getpwuid*().  getpwnam*() truncates to MAXLOGNAME - 1
when reading from a file (breaking at least sh, tcsh and bash)
and utilities such as su(1) check, complain and fail if the
passed name is >= MAXLOGNAME in length.

MFC after:	3 weeks

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase