circuit_board: fix last issues (J26 wrong part + U1 PCB version + U1 write enable option + Front LEDs RF & WR status swap)

circuit_board: modification of PCB dimensions and some connectors placement to improve enclosure design. Review of ground planes and polygons. Modification of microUSB connector.

circuit_board: change TMP101 (temperature sensor) power supply from P3V3_REG to P3V3 (available following power sequence).

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.