server.ip may be NULL

We no longer make connections based on IP address, but based on the domain
name of the XMPP server component. After a transitional period has passed,
this column should be dropped from the table.
Comment on legacy-ness of servers.ip column.
new table: remote storage connection for accounts
save storage URL for remote storage
Some column cleanup.  Add accounts.new_post_in_river column.
Revert "save storage URL for remote storage"

This reverts commit d014f61a04fa08cf1b64c31a93549ddf9713f11b.
Revert "new table: remote storage connection for accounts"

This reverts commit f86e940901df9d442855cf82c95ff13c2a4ff969.
make database host and password optional
new column to record the reason for retrying a job
Merge branch 'master' into xmpp
Merge branch 'master' into xmpp
account setting: hide markdown bar
fix: stricter spring-url constraint
new account setting: forward DMs via email
store public key for email encryption with accounts
speed up post loading by adding post_id index on comments table
speed up slow queries with indices
Merge branch 'master' into xmpp
Merge branch 'master' into xmpp
Merge branch 'master' into xmpp