DBManager: Fixed upgrade version detection for MariaDB.
DBManager: Updated mysqldump invocation to mysql 4.0 and later.

The mysqldump option "--all" apparently changed name to
"--create-options" some time after mysql 3.23.

Fixes database backups with current versions of mysqldump.

Fixes some of [bug 6126].
Merge branch 'patches/bug6126' into devel

* patches/bug6126:
  DBManager: Updated mysqldump invocation to mysql 4.0 and later.
Pike 8.0: Change static to protected.

Pike 8.0 warns about use of this old keyword.
Merge branch 'patches/pike8.0' into devel

* patches/pike8.0:
  Pike 8.0: Change static to protected.