(ITS#3528) add time limit options for bind and exop requests

[nalin@redhat.com]

Full_Name: Nalin Dahyabhai
Version: 2.2.23
OS: Linux 2.6
URL: http://people.redhat.com/nalin/test/openldap-2.2-timeouts.patch
Submission from: (NULL) (66.187.230.200)


If I'm reading the code right, all bind requests and exop requests issued by
libldap are allowed to block indefinitely.

In cases where a TCP connection to a server will succeed, but the server is
unresponsive (one contrived example would be if the server were stopped by
SIGSTOP), a client which connects and attempts a simple bind will block until
the server responds, which may be never.

Additional API-level options which influence this behavior on the client side
could be useful for working around this scenario.