Lots of features, first version that reliably crawls Geminispace.

- [x] Concurrent downloading with workers
- [x] Concurrent connection limit per host
- [x] URL Blacklist
- [x] Save image/* and text/* files
- [x] Configuration via environment variables
- [x] Storing snapshots in PostgreSQL
- [x] Proper response header & body UTF-8 and format validation
.

.

db/restore-table.sql

@@ -0,0 +1,9 @@
+BEGIN;
+
+SET statement_timeout = '10min';
+
+TRUNCATE TABLE snapshots;
+
+INSERT INTO snapshots SELECT * FROM backup;
+
+COMMIT;