Remove this provider type, as well as any references in the docs and
examples to the "LEGACYLOCAL" migration domain.

Fixes: #165

Remove the "legacy" option from examples and man pages.
Legacy is is finally R.I.P

Add docs for ldapSchema in sssd-ldap man page.

Remove magicPrivateGroups since it's set automatically, use bool values
for enumerate.

Also add a notice about krb5 auth-module with a link to specialized
manpage to sssd.conf(5) similar to what we have for ldap auth-module.
Move both outside proxy domain description.

This timeout specifies the lifetime of a cache entry before it is
updated out-of-band. When this timeout is hit, the request will
still complete from cache, but the SSSD will also go and update
the cached entry in the background to extend the life of the
cache entry and reduce the wait time of a future request.

Added man pages sections about user and group attribute mapping.
Added an example configuration to access an AD server.

This patch introduces provider=files as a valid provider.
Upon loading the backend, its properties in confdb are overwritten to
those that represent legacy local domain.

Also document this in sssd.conf(5) and example config

The libPath should be constructed from the libName. There is no
benefit to specifying it separately.

The local provider needs no backend, so we'll create a special
provider entry for it called "local" that will not attempt to
retrieve provider configuration but will remain in the service
list so it can be updated when the config file changes.

Previously, every DP client was allowed to set its own "retries"
option. This option was ambiguous, and useless. All DP clients
will now use a global option set in the services config called
"reconnection_retries"