Move IPv6 around and to ecto_sql repo

Author: josevalim

README.md

@@ -81,23 +81,6 @@ See the [getting started guide](https://hexdocs.pm/ecto/getting-started.html) an
 
   * [The Little Ecto Cookbook](https://dashbit.co/ebooks/the-little-ecto-cookbook), a free ebook by Dashbit, which is a curation of the existing Ecto guides with some extra contents
 
-### IPv6 support
-
-Does not happen automagically. If your database's host resolves to ipv6 address you should
-add `socket_options: [:inet6]` to configuration block like below:
-
-```elixir
-import Mix.Config
-
-config :your_app, :tds_conn,
-  hostname: "db12.dc0.comp.any",
-  username: "test_user",
-  password: "test_password",
-  database: "lomaster",
-  port: 1433,
-  socket_options: [:inet6] # here you may also add all the options for `gen_tcp` erlang module
-```
-
 ## Usage
 
 You need to add both Ecto and the database adapter as a dependency to your `mix.exs` file. The supported databases and their adapters are:
@@ -142,6 +125,20 @@ defmodule MyApp.Repo do
   ...
 ```
 
+### IPv6 support
+
+If your database's host resolves to ipv6 address you should
+add `socket_options: [:inet6]` to configuration block like below:
+
+```elixir
+import Mix.Config
+
+config :my_app, MyApp.Repo,
+  hostname: "db12.dc0.comp.any",
+  socket_options: [:inet6],
+  ...
+```
+
 ## Supported Versions
 
 | Branch            | Support                  |

guides/introduction/Getting Started.md

@@ -119,49 +119,6 @@ This tells our application about the repo, which will allow us to run commands s
 
 We've now configured our application so that it's able to make queries to our database. Let's now create our database, add a table to it, and then perform some queries.
 
-### IPv6 support
-
-Does not happen automagically. If your database's host resolves to ipv6 address you should
-add `socket_options: [:inet6]` to configuration block like below:
-
-```elixir
-import Mix.Config
-
-config :your_app, :your_connection,
-  hostname: "db12.dc0.comp.any", # just an example
-  socket_options: [:inet6] # here you may also add all the options for `gen_tcp` erlang module
-  # ... other options
-```
-
-### Unix socket connection
-
-For faster communication, you may consider communicating with Postgres via Unix sockets.
-If your PG server was started on the same machine as your code, you could check that.
-
-```bash
- % sudo grep unix_socket_directories /var/lib/postgres/data/postgresql.conf
-unix_socket_directories = '/run/postgresql'
-```
-
-```bash
-% ls -lah /run/postgresql
-итого 4,0K
-drwxr-xr-x  2 postgres postgres  80 июн  4 10:58 .
-drwxr-xr-x 35 root     root     840 июн  4 21:02 ..
-srwxrwxrwx  1 postgres postgres   0 июн  5 07:41 .s.PGSQL.5432
--rw-------  1 postgres postgres  61 июн  5 07:41 .s.PGSQL.5432.lock
-```
-
-So you have postgresql started and listening on the socket.
-
-Add then this line to config block:
-
-```elixir
-config :your_app, :your_connection,
-    # ...
-    socket_dir: "/run/postgresql"
-```
-
 ## Setting up the database
 
 To be able to query a database, it first needs to exist. We can create the database with this command:
@@ -751,9 +708,9 @@ changeset = Friends.Person.changeset(person, %{first_name: ""})
 Friends.Repo.update(changeset)
 #=> {:error,
      #Ecto.Changeset<
-       action: :update, 
+       action: :update,
        changes: %{},
-       errors: [first_name: {"can't be blank", [validation: :required]}], 
+       errors: [first_name: {"can't be blank", [validation: :required]}],
        data: #Friends.Person<>,
        valid?: false
      >}