open file descriptors is greater than FD_SETSIZE minus SAFETY_MARGIN,
also skip the test if any of the open file descriptors has a number
greater than FD_SETSIZE minus SAFETY_MARGIN.

<sys/time.h>.

of poll() and select() happens to be bound by FD_SETSIZE

timval.c dependency on some of those

lib/timeval.c source code since those functions are not in the API (and might
not be accessible)

  header, you got _two_ User-Agent headers in the CONNECT request...! Added
  test case 287 to verify the fix.

SSL conditions not being the same

added distclean target.

  platforms.