[twitter] change some defaults

- 'retweets' option: true -> false
- 'quoted' option  : true -> false

  i.e. disable downloading tweets from other user's timelines by default

- search directory:
    '["{category}", "Search", "{search}"]' ->
    '["{category}", "{user[name]}"]'

  i.e. change it to the same as other twitter extractors (#1308)

docs/gallery-dl.conf

@@ -256,9 +256,9 @@
             "password": null,
             "cards": false,
             "conversations": false,
-            "quoted": true,
+            "quoted": false,
             "replies": true,
-            "retweets": true,
+            "retweets": false,
             "text-tweets": false,
             "twitpic": false,
             "users": "timeline",