circuit_board: removed D flip-flop on DOUTA signals (with associated RF clock delay and fanout). Re-routed DOUTA signals with LVDS-to-LVPECL translators.

circuit_board: fix issue #18. Tuning length done. Ready for new stackup. Remaining DRC errors are the same as in the initial V1 PCB project delivered by supplier.

circuit_board: issue #18. Second SFP (replacing SATA) placed and routed. Still Differential Pair DRC error (tuning length missing).

circuit_board: issue #18. SATA replaced by SFP in schematics. Imported in PCB, but not placed nor routed yet.