Merge branch '0.7.x' into 0.8.x

diff --cc db/laconica.sql
index 20f0cabd17c070e2ad2ae5b4cdd96b06a3abcb87,5b57494d984d6cee4b92b1b4e0f5b7325d283e0b..83d610f0d37be196d2a9aa2beb43a1c7fc94ff03
--- 1/db/laconica.sql
--- 2/db/laconica.sql
+++ b/db/laconica.sql
@@@ -114,11 -114,10 +114,12 @@@ create table notice 
      reply_to integer comment 'notice replied to (usually a guess)' references notice (id),
      is_local tinyint default 0 comment 'notice was generated by a user',
      source varchar(32) comment 'source of comment, like "web", "im", or "clientname"',
 +    conversation integer comment 'id of root notice in this conversation' references notice (id),
  
      index notice_profile_id_idx (profile_id),
 +    index notice_conversation_idx (conversation),
      index notice_created_idx (created),
+     index notice_replyto_idx (reply_to),
      FULLTEXT(content)
  ) ENGINE=MyISAM CHARACTER SET utf8 COLLATE utf8_general_ci;