sieve_storage_do_create_personal() will go away.

Should make later commit yield clearer diff.

Later, this is needed to allow retrieving a global script from one of many
storages, rather than just one.

lib-sieve: storage: ldap: sieve-ldap-storage-settings - Use settings as parameter to sieve_ldap_settings_check() directly

lib-sieve: storage: file: sieve-file-storage - Move debug logging in sieve_file_storage_autodetect()

lib-sieve: storage: file: sieve-file-storage - Move storage creation in sieve_file_storage_autodetect()

lib-sieve: storage: file: sieve-file-storage - Perform write check earlier in sieve_file_storage_do_autodetect()

lib-sieve: storage: file: sieve-file-storage - Merge sieve_file_storage_autodetect() into sieve_file_storage_do_init_default()

For now, these yield the same result.

Open the default storage separately, rather then the script directly.

lib-sieve: plugins: include: ext-include-common - Allow retrieving global scripts from several storages

This allows adding storage class plugin support.