We don't use the ftime function on unix for filling SWelsTime anyway,
we fill the time and millitm fields manually.
On android, the sys/timeb.h header has been removed in the next
platform version (currently available in NDK r10 in the "L preview"
release), since this header and the ftime function have been removed
from the POSIX 2008 specification.
This fixes compilation when targeting the Android "L preview" release,
even when targeting the 32 bit ABIs.
