Bug 6540 - Add config file as command line option for koha-create

Bug 6540 - Add config file as command line option for koha-create

Order of precedence for config options, from lowest to highest:

1. The defaults set in koha-create itself
2. /etc/koha/koha-sites.conf
3. Config file specified with --configfile
4. Individual options set with --marcflavor, --zebralang, --defaultsql

Signed-off-by: Robin Sheat <robin@catalyst.net.nz>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit b66c860d5df65c185279741219b88bc08e7de524)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>