Rewrite of commit f35bb686.

Bug 7340.

Wrapping the plugin interface with an #ifdef block as was previously
done still results in the plugin being generated, but without any
of the plugin symbols present. This will then cause errors when
running user commands similar to:
error: Couldn't load specified plugin name for switch/cray_aries: Plugin name/type/version symbol missing

Bug 7017.

Bug 7017.

Bug 7017.

Bug 7017.

Variable only used within #if HAVE_PTY_H, and thus causes build failure
if building without <pty.h>.

Bug 7017.

Bug 7017.

Needed for WTERMSIG macro.

Bug 7017.

Bug 7017.

Bug 7017.

Bug 7320

Bug 7320

This makes it so that the backup will reinint the fed_mgr and load fed
state when a backup takes over on subsequent takeovers.

Bug 7320

Bug 7441.

Bug 7441.

Bug 7441.

Bug 7441.

Bug 7441.

Remove misleading reference to the deprecated MAX_AGENT_CNT macro.

Bug 6855.

The '[<a name="top">]*' part matched any of those characters, not the
exact phrase as was presumably intended. Fix that by matching it, and
naming the group we are actually searching for as 'title'.

Fixes nss_slurm.html and pam_slurm_adopt.html having incorrect titles of
"ss_slurm" and "_slurm_adopt" respectively.

Fixes a compilation issue with the job_container/cncu plugin.

Bug 7398

Bug 6772, 6977.

Causes build failures on Debian ia64 platform, and per the glibc docs this
is an internal macro for them that should be getting set automatically
as long as we've defined _GNU_SOURCE before including our first glibc
header.

Fix the task/affinity plugin code to define _GNU_SOURCE first, and not
defer this to the affinity.h include (which may come after some glibc
headers have been included, leading to issues finding the CPU_SETSIZE
macro).

Bug 7152.

No functional changes.

Bug 7402.

If plugin load fails, then slurmd will SEGFAULT later while attempting
to call one of the invalid function pointers. Instead, just abort during
loading.

Bug 7402.

If only allowing particular alloc nodes in a partition, deny any request coming from an alloc node of NULL.

Bug 7255

Bug 7318.

Bug 7363.

Bug 7353.

Account coordinators are allowed to add users to their accounts, but
cannot change the default account of a user. However, when a user is
added to an account and the user doesn't have an account yet, the
account is set as the user's default account, which counts as changing
the user's default account. This commit allows account coordinators to
add users who don't already have a default account elsewhere to the
accounts they are coordinators over.

Bug 7018.

Fixes a compilation issue with the job_container/cncu plugin.

Bug 7398