Improve geo bypass mechanism

* Introduce geo bypass context
* Add ability to bypass based on IP blocks in CIDR notation
* Introduce --geo-bypass-ip-block

youtube_dl/__init__.py

@@ -430,6 +430,7 @@ def _real_main(argv=None):
         'config_location': opts.config_location,
         'geo_bypass': opts.geo_bypass,
         'geo_bypass_country': opts.geo_bypass_country,
+        'geo_bypass_ip_block': opts.geo_bypass_ip_block,
         # just for deprecation check
         'autonumber': opts.autonumber if opts.autonumber is True else None,
         'usetitle': opts.usetitle if opts.usetitle is True else None,