function(s) using SessionHandle pointers

something went wrong like it got a bad response code back from the server,
libcurl would leak memory. Added test case 538 to verify the fix.

I also noted that the connection would get cached in that case, which
doesn't make sense since it cannot be re-use when the authentication has
failed. I fixed that issue too at the same time, and also that the path
would be "remembered" in vain for cases where the connection was about to
get closed.

responded with a single status line and no headers nor body. Starting now, a
HTTP response on a persistent connection (i.e not set to be closed after the
response has been taken care of) must have Content-Length or chunked
encoding set, or libcurl will simply assume that there is no body.

To my horror I learned that we had no less than 57(!) test cases that did bad
HTTP responses like this, and even the test http server (sws) responded badly
when queried by the test system if it is the test system. So although the
actual fix for the problem was tiny, going through all the newly failing test
cases got really painful and boring.

This is done to back out changes done in revisions 1.77 and 1.75

This is done to back out changes done from revisions 1.213 to 1.217

This is done to back out changes done from revisions 1.6 to 1.10

have proper TERM and INT signal handlers implemented.

servers hash, and adjust message arguments accordingly.

be clear of warnings. Uncomment it if this module is further modified.

The "warnings" module requires perl 5.006 or later. Previous perl
versions don't have it and die on missing modules.

If the list has only one item avoid sort subroutine.

server holds not only its two main pids, but also the pidfile of the test
server and the 'slavepidfiles' for ftp* servers. This allows a better control
when stopping servers.

Now from runtests.pl when test servers are stopped they are signalled in
sequence TERM, INT and KILL allowing time in between for them to die. This
will give us a chance of gracefully stopping test servers, which we didn't
have when we were killing them in first instance.

Add failure checking for servers when fork()ed.

Use same code path in 'stopserver' when called with a single or multiple pids.

behaviour some versions of IRIX exhibit of committing suicide on big
mallocs instead of just returning a friendly null pointer

fix closing of fd's when limit is reached

when more than FD_SETSIZE file descriptors are open.
This means that if for any reason we are not able to
open more than FD_SETSIZE file descriptors then test
518 should not be run.

test 537 is all about testing libcurl functionality
when the system has nearly exhausted the number of
free file descriptors. Test 537 will try to run with
very few free file descriptors.

In this way we'll be able to sort out problems that might
arise in the prechek phase of the 518 test.

Once that 518 has been verified this change will be undone.

preventing execution of this test on many platforms

on Win32.

- Take in account RLIM_INFINITY.
- Verify that soft limit is actually changed when doing so.
- Show errno in case getrlimit or setrlimit fails.
- Keep file descriptors open only while runing this test.

case when 401 or 407 are returned, *IF* no auth credentials have been given.
The CURLOPT_FAILONERROR option is not possible to make fool-proof for 401
and 407 cases when auth credentials is given, but we've now covered this
somewhat more.

You might get some amounts of headers transferred before this situation is
detected, like for when a "100-continue" is received as a response to a
POST/PUT and a 401 or 407 is received immediately afterwards.

Added test 281 to verify this change.