Scan the directory `plugin_path` for plugin packages and loads them.

def _get_spyderplugins(plugin_path, is_io, modnames, modlist):
    """Scan the directory `plugin_path` for plugin packages and loads them."""
    if not osp.isdir(plugin_path):
        return

    for name in os.listdir(plugin_path):
        # This is needed in order to register the spyder_io_hdf5 plugin.
        # See issue 4487
        # Is this a Spyder plugin?
        if not name.startswith(PLUGIN_PREFIX):
            continue

        # Ensure right type of plugin
        if is_io != name.startswith(IO_PREFIX):
            continue

        # Skip names that end in certain suffixes
        forbidden_suffixes = ['dist-info', 'egg.info', 'egg-info', 'egg-link',
                              'kernels']
        if any([name.endswith(s) for s in forbidden_suffixes]):
            continue

        # Import the plugin
        _import_plugin(name, plugin_path, modnames, modlist)