cf-serverd: free getaddrinfo() result, on error of OpenReceiverChannel()

getaddrinfo() may allocate the 'result' struct even in cases where it
will return an error. Take care to free memory, although we would exit
the server process anyway.
cf-serverd: getaddrinfo() will use a numeric port, no lookup

This `AI_NUMERICSERV` flag avoids looking up the "services" table for
a string port resolution, according to the manual.
cf-serverd: getaddrinfo() will NOT set "errno" upon failure

It has its own `gai_strerror()` function to resolve its (reentrant)
result code.
cf-serverd: fix typo for addrinfo constant

As spotted by Dimitrios Apostolou
Leak-fix in FnCallRegExtract().

One of its premature returns neglected to free the arrayname.
remove export_zenoss constraint
Removing buggy undocumented feature ...

... according to discussion at
https://github.com/jimis/core/commit/d4999f291bf937ef36ee05c28149ca773b172865
Fix selectservers().

See Redmine #5458. Thanks to Bob Ingersoll for spotting it.
Add acceptance test for selectservers().
TryConnect() should return error when select() times out.
Logging in milliseconds is ugly.
Fix socket descriptor leak.
Acceptance test for selectservers() now checks failures as well as successes.

Unfortunately some requests may timeout, which means that the test will
take 30s to complete. In the future we should enable parallel test
harness to avoid waiting.
Selectservers() now logs INFO in case of timeout.
Beautify message.
Fix package_list_update_ifelapsed having no effect on "apt-get update"

Redmine #3981, #5339.

It is documented as having the described effect, but does not.

The timestamp for the last update is now maintained by a timestamp
file, /var/cfengine/state/software_update_timestamp_<manager>, where
<manager> is the package executable that is being used for the current
promise.
Ideally it should be integrated with the database, but we want the low
risk solution right now, and we plan to replace this code anyway.
Use dcs_passif_expected() to check and report all classes are set.
Change timeout so that acceptance test takes only 5 seconds instead of 30.

Does not work for now, should work after redmine #5497 gets fixed.
tests/acceptance/01_vars/02_functions/staging/maparray.cf: minor changes, still in staging
Redmine #4312: Fix incorrect file location for backup repository.

Canonifying and appending the file name was done twice, so the fix
was simply to remove the first pass.