(core): dataReg modules are boring
Description
We need data libraries (data, arData, *Data) to be loaded right at the beginning of the XML configuration parsing. Since services modules are not yet loaded at this stage, data libraries with which they link are not in memory. To solve that, special modules were introduced a long time ago to load the libraries. They are counter-intuitive, hackish, error-prone, so to sum up, they suck hard.
Proposal
Replace them by a simple and direct dl_load()
of the data library when parsing the configuration.