This is an interim solution for supporting HSM failover by automatically
shutting down the server when signing key becomes inaccessible.
At auto-shutdown, a crumb fiile will be left in the instance directory
for an external daemon to detect and restart, if necessary.
Due to limitation of the watch dog (nuxwdog) at present time,
the restart option currently only works if started with watch dog (nuxwdog),
and it will prompt for passwords on the terminals.
The restart counter is to prevent the server from going into an infinite restart
loop. Administrator will have to reset autoShutdown.restart.count to 0 when max
is reached.

(cherry picked from commit 5a9ecad9172f76ca1b94b40aedcdd49d009aceb1)

Various codes have been modified to properly stop threads during
shutdown. A new ID attribute has been added to the LDAP connection
factory classes to help identify leaking threads.

https://fedorahosted.org/pki/ticket/1327

The CA installation process requires starting with the profile
subsystem disabled, then enabling it once profiles have been loaded
into the database.  Accordingly, to avoid hacks with hardcoded
offsets, add the "enabled" CS.cfg configuration parameter along with
methods to enable or disable a subsystem based on the subsystem ID.

A disabled subsystem does not have its `init` method called, but it
is still instantiated and added to the registry so that other code
can look up a subsystem by name and find out its class.

Subsystems are enabled by default.

This commit also removes an assumption that the subsystem config
sub-store names are sequential numbers beginning at `0`.

The test classes have been moved from base/common/test to base/server/test
and into the cmscore package because they are dependent on server classes.