Also revamp SetLastError et al; Instead of taking status by pointer,
take by value and return new status instead. Rename from SetLast to Make
to make this new usage obvious.
Also move declarations for the error functions from duplicated in the
per-target HALInternal.hpp to a common ErrorHandling.hpp.
- Remove status return from HAL level (clock getting should never fail)
- Remove 32-bit timestamp expand function
- Make monotonic_clock.hpp (formerly fpga_clock.hpp) header-only and
move to root hal include directory
