PDC core version 749 - minor update

[Mike Sanders]

Plagiarism Detector core version 749 minor update.

Features added:

+ Advanced Text Extraction engines (TEEs) configuration in Document Manager.
+ Alternative TEEs added.
+ Added auto-configuration of TEEs (not active yet).
+ REP sub-core completely rewritten thread-safe.
+ Much faster REP turnaround time.
+ Removed final REP timeout.
+ Same results for Q-Cache and Direct Download.

- iFIlters diagnostics removed.