PR:		6259
Reviewed & slightly modified by:	phk
Submitted by:	Archie Cobbs <archie@whistle.com>

function from 'errno' to 'error' so that there is no conflict with the
thread-safe definition of errno in errno.h.

can return UNIX errnos.  When UNIX errnos catch up with FTP status
codes (e.g. at 100) a new way will have to be found to tell which
is which.

This allows fetch to print errors like
fetch: ftp.fu-berlin.de: No route to host
instead of
fetch: ftp.fu-berlin.de: Unknown error

nuked file descriptor.  This is probably why sysinstall's ftp xfer
occasionally SEGV'd if you left things alone for a long time and
the timeout code got called.  Whoops!

plain 0 should be used.  This happens to work because we #define
NULL to 0, but is stylistically wrong and can cause problems
for people trying to port bits of code to other environments.

PR:		2752
Submitted by:	Arne Henrik Juul <arnej@imf.unit.no>

just going to hang forever on the close).

the handler with SA_RESTART set, so the system calls I wanted to have the
timeout effect will just restart instead (which is NOT what I wanted).
Sheepishly use sigaction() like a good boy and make timeouts actually do
something.

Also pass errors out more effectively so that fetch(1) actually understands
what went wrong.