Fix: Renaming add-on directory and updating index.json

- Add-on directory name was not a proper identifier before.
- index.json was formatted incorrectly (missing commas); new version is generated with updated generate-json.py (which seems to fail for addons_contrib at the moment), and contains data for add-ons in addons repo.

package_manager/networking.py

@@ -0,0 +1,76 @@
+# ====================== BEGIN GPL LICENSE BLOCK ======================
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 3
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# ======================= END GPL LICENSE BLOCK ========================
+
+import bpy
+import json
+import urllib.request
+
+
+class UpdateIndex(bpy.types.Operator):
+    """Update the list of add-ons available for download"""
+    bl_idname = "wm.update_index"
+    bl_label = "Update list of add-ons"
+
+    def execute(self, context):
+        try:
+            req = urllib.request.urlopen("https://git.blender.org/gitweb/gitweb.cgi/"
+                "blender-package-manager-addon.git/blob_plain/HEAD:/addons/index.json")
+            index_file = req.read()
+            del req
+        except urllib.error.HTTPError as err:
+            self.report({'ERROR'}, "Error requesting update: "
+                + str(err.code) + " " + err.reason)
+            return {'CANCELLED'}
+        
+        try:
+            addon_list = json.loads(index_file)
+        except ValueError:
+            self.report({'ERROR'}, "Error: JSON file could not parse.")
+            return {'CANCELLED'}
+        
+        for addon_list["addons"] as name, content:
+            addon = PackageManagerAddon()
+            addon.name = name
+            addon.source = content["source"]
+            addon.description = content["description"]
+            addon.author = content["author"]
+            addon.wiki_url = content["wiki_url"]
+            addon.tracker_url = content["tracker_url"]
+            addon.location = content["location"]
+            addon.category = content["category"]
+            for content["version"] as item:
+                # TODO: add multi-version functionality
+                for item as version, value:
+                    addon.version = key
+                    addon.blender = value["blender"]
+                    addon.support = value["support"].upper()
+                    try:
+                        addon.warning = content["warning"]
+                    except Exception:
+                        pass
+                    addon.filename = value["filename"]
+        
+        print(index_file)
+        
+        return {'FINISHED'}
+
+
+def register():
+    bpy.utils.register_class(UpdateIndex)
+
+def unregister():
+    bpy.utils.unregister_class(UpdateIndex)