.xql overhaul: - removed misleading sql-statements from db_* calls, which were ignored due .xql files - removed bug where same query name was used in a single proc with different intended sql queries, but the same was picked up from the .xql file due to the name - removed multiple entries of same query name from .xql files (e.g. the entry "package_create_attribute_list.select_type_info" was 7 (!!!) times in a single .xql file) - removed redundant queries for unsupported versions of the dbms - added missing xql entries for db-backends, where other db-specific queries exists (e.g. added an entry to -oracle.xql, where an entry existed in -postgres.xql)