The server may segfault during the last stages of cleanup during shutdown
after unloading the auth LDAP plugin. This is because the ldap library
will configure SSL to use locking callbacks in the LDAP library.
After unloading libldap, these callbacks point to non-existant code.

For valgrind builds, we add a dependency on the server executable to ldap,
ensuring that ldap will not be unloaded when unloading plugins.
This allows valgrind to see the suppressions we have in valgrind.supp.

For OpenSSL in the 1.0.x series we also add the dependency,
to ensure clean shutdown of the server.

Generalized some valgrind suppressions to match misc OS/compiler combinations.

Change-Id: I6264bda57e0498bf552ed9c805b350724a2dbc5c