Adding the lodelsites_em.py for EM generation

No knowing what datahandler ought to be used for em_groups, I simply set
'text' in place of it. To be changed accordingly

lodelsites_em.py

@@ -0,0 +1,68 @@
+#!/usr/bin/python3
+#-*- coding: utf-8 -*-
+
+from lodel.context import LodelContext
+LodelContext.init()
+
+from lodel.settings.settings import Settings as settings
+settings('globconf.d')
+from lodel.settings import Settings
+
+from lodel.editorial_model.components import *
+from lodel.editorial_model.exceptions import *
+from lodel.editorial_model.model import EditorialModel
+
+em = EditorialModel('LodelSites', 'LodelSites editorial model')
+
+base_group = em.new_group(
+    'base_group',
+    display_name = 'Base group',
+    help_text = 'Base group that implements base EM features (like classtype)'
+)
+
+em_lodel_site = em.new_class(
+    'LodelSite',
+    group = base_group,
+    abstract=True
+)
+
+em_lodel_site.new_field(
+    'name',
+    display_name = 'lodelSiteName',
+    help_text = 'Lodel site full name',
+    group = base_group,
+    data_handler = 'varchar'
+)
+
+em_lodel_site.new_field(
+    'shortname',
+    display_text = 'lodelSiteShortName',
+    help_text = 'Lodel site short string identifier',
+    group = base_group,
+    data_handler = 'varchar',
+    max_length = 5,
+    uniq = True
+)
+
+em_lodel_site.new_field(
+    'extensions',
+    display_text = 'lodeSiteExtensions',
+    help_text = 'Lodel site extensions',
+    group = base_group,
+    data_handler = 'list',
+    back_reference = ('Plugin', 'plugin_name') 
+)
+
+em_lodel_site.new_field(
+    'em_groups',
+    display_text = 'lodelSiteEmGroups',
+    help_text = 'Lodel site EM groups',
+    group = base_group,
+    data_handler = 'text',
+)
+
+pickle_file_path = 'examples/lodelsites_em.pickle'
+xml_file_path = 'examples/lodelsites_em.xml'
+
+em.save('xmlfile', filename=xml_file_path)
+em.save('picklefile', filename=pickle_file_path)