Add jackrabbit-schema.sql file to drop all the tables, to be used with both jahia:configure maven goal and configuration wizard.

When we are using other database than MySQL, we do not drop the database, and therefore the content of the Jackrabbit tables is never purged. We should do this by adding a schema file that would at the minimum drop the tables (that will be re-created by Jackrabbit's startup). Here is an example of such a script :

drop table JR_DEFAULT_BINVAL;
drop table jr_default_bundle;
drop table jr_default_names;
drop table jr_default_refs;
drop table jr_default_seq_names_id;
drop table jr_fsdefault_fsentry;
drop table jr_fsg_fsentry;
drop table jr_fsv_fsentry;
drop table jr_v_binval;
drop table jr_v_bundle;
drop table jr_v_names;
drop table jr_v_refs;
drop table jr_v_seq_names_id;