Separate config types into a look-up table and constrain cfg_config's config_type field to only accept one of those
values. This is just a create script for postgresql right now - will need migrate and create scripts for other DBs once
fully tested.
Update SelectTypes query to fetch types from the new cfg_type table, in order to improve the performance of this
frequent query. New InsertType and SelectTypeWhere elsql macros are defined for checking if a particular config
type exists, and to insert a new config type in the cfg_type table. The insert() method in DbConfigWorker now
automatically adds any previously unseen config type to the cfg_type table, so the behaviour is still largely the
same as before.
Create & migrate scripts for version 47 of the config db. These create a cfg_type table, constrains cfg_config's
config_type field to use a type name specified in cfg_type, and populates the newly created cfg_type table with
distinct config type names from cfg_config.
Remove 'WITHOUT oids' from hsql and sqlserver2008 config db upgrade scripts
Update AbstractDbConfigMasterWorkerTest so that the newly introduced config type lookup table is populated at setup.
Initial version of master cache: get by oid and uid implemented, indexing by version/correction ranges as well as uids.
Add/update/correct etc. just forward request to underlying master. Change management untested.