* [SC] Updated the predicate documentation headers in several modules to conform to plDoc v2 syntax.
Yet another step towards more modular codebase and reuse of existing predicates from the PGC.

* [PICARTA_SCRAPE,NEW] New module containing the code around PICARTA_QUERY needed to walk though all the Picarta content (for a given list of PPNs) and to store the query results locally.
* [STCN,SC] Relocated lots of code to other modules. This will at some point only contain the script for constructing the STCN dataset (maybe renaming it to STCN_SCRIPT).
* [STCN_GENERIC,NEW] New module, containing predicates previously in STCN that were used by other modules as well.
* [STCN_KMC,EXT] Finalized the conversion of the KMC-related predicates from module STCN_PARSE to this module.
* [STCN_PARSE,EXT] Big overhaul of this module: statements are parsed by DCGs, uses the newly added DCG rules in module, DCG_GENERIC.
* [STCN_SCHEMA,SC] Use of higher level RDFS assertions (module RDFS_BUILD) simplified code.