backplane signal names
- CPCI-S_Backplane_P1-P3: SYSSLOT_N rename to SYSEN_N
- CPCI-S_Backplane_P1-P3: remove SH_B[x] labels around J1C, J1D
- CPCI-S_Backplane_P1-P3: the labels that indicate original CPCI-S naming of backplane signals could be made smaller or even completely removed not to pollute the schematics.
- CPCI-S_Backplane_P1-P3: PSU_PPRESx rename to P_PRESx to keep compatibility with DI/OT specification