chore, check for sys/time.h and time.h

So, for instance, um-netdania will include them and not throw
a warning about implicit gettimeofday() declaration.

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'code/hygiene' into next

* code/hygiene:
  chore, check for sys/time.h and time.h
Merge branch 'next'

* next:
  chore, check for sys/time.h and time.h
  chore, chuck proto-* gperf definitions
  chore, chuck pf-tws as it is now in twsgluum