syscall: update makeversion to build sysinfo properly, and add num procs

Also add a geometry ioctl for hd drivers (not yet wired up)
syscalls.h: update sysinfo block
sysconf: use nproc value
pathconf: doesnt use sysinfo so don't fetch it
fdisk: Now we are doing PC style partition tables import an fdisk tool
limits.h: remove extra #endif
Merge pull request #32 from willsowerbutts/toupstream

Toupstream
devsdspi: mark table const
README.md: Will's SD merged, so update the README
Merge remote-tracking branch 'alan/master'
Kernel: n8vem-mark4: Optimise SD SPI routines to run faster, and drop
the large precomputed table. Rename block send/receive routines with
clearer names.