'Loads all sections starting with section_prefix and returns a
dictionary containing the name and dictionary of settings for each
section.
keys --> section name (as returned by self._get_section_name)
values --> dictionary of settings for a given section
e.g.
$ print self._load_sections(\'volumes\', self.plugin_settings)
{\'myvol\': {\'__name__\': \'volume myvol\',
\'device\': None,
\'mount_path\': \'/home\',
\'partition\': 1,
\'volume_id\': \'vol-999999\'},
\'myvol2\': {\'__name__\': \'volume myvol2\',
\'device\': None,
\'mount_path\': \'/myvol2\',
\'partition\': 1,
\'volume_id\': \'vol-999999\'},'

def _load_sections(self, section_prefix, section_settings, filter_settings=True):

    sections = self._get_sections(section_prefix)
    sections_store = AttributeDict()
    for sec in sections:
        name = self._get_section_name(sec)
        sections_store[name] = self._load_section(sec, section_settings, filter_settings)
    return sections_store
