Put client plugins into -common rpm, not -shared.
Because they're needed for
* all clients that link with shared libmysqlclient (-shared)
* our clients from -client rpm, they're statically linked (-client)
* the server that acts as a replication slave (-server)
out of libmysql into separate dynamic plugins in the plugin/ directory.
move dialog and auth_socket plugins out of the plugin directory with examples into
dedicated directories in plugin/