Simplify example instructions and fix broken examples

Also convert to AsciiDoc while we're at it.

examples/rest_pastebin/README.asciidoc

@@ -1,59 +1,46 @@
-REST pastebin example
-=====================
+= REST pastebin example
 
 To try this example, you need GNU `make` and `git` in your PATH.
 
-To build the example, run the following command:
+To build and run the example, use the following command:
 
-``` bash
-$ make
-```
+[source,bash]
+$ make run
 
-To start the release in the foreground:
+Then point your browser to http://localhost:8080
 
-``` bash
-$ ./_rel/rest_pastebin_example/bin/rest_pastebin_example console
-```
-
-Then point your browser at [http://localhost:8080](http://localhost:8080).
-
-Usage
------
+== Usage
 
 To upload something to the paste application, you can use `curl`:
 
-``` bash
+[source,bash]
 $ <command> | curl -i --data-urlencode paste@- localhost:8080
-```
 
 Or, to upload the file `my_file`:
 
-``` bash
+[source,bash]
 curl -i --data-urlencode paste@my_file localhost:8080
-```
 
 The URL of your data will be in the location header. Alternately, you can visit
 http://localhost:8080 with your favorite web browser and submit your paste via
 the form.
 
 Code that has been pasted can be highlighted with ?lang=<language> option if
-you have [highlight](http://www.andre-simon.de/doku/highlight/en/highlight.html)
+you have http://www.andre-simon.de/doku/highlight/en/highlight.html[highlight]
 installed (although `pygments` or any other should work just fine).
 
 This will show the contents of the HTML file:
 
-``` bash
+[source,bash]
 curl -i --data-urlencode paste@priv/index.html localhost:8080
 curl <url from location header>
-```
 
 If your terminal supports color sequences and `highlight` is installed,
 the following command will show the same contents but with HTML syntax
 highlighting.
 
-``` bash
+[source,bash]
 curl <url from location header>?lang=html
-```
 
 If you open the same URL in your web browser and your web browser tells
 Cowboy that it prefers HTML files, you will see the file highlighted

examples/rest_pastebin/src/toppage_handler.erl

@@ -16,7 +16,7 @@
 -export([paste_text/2]).
 
 init(Req, Opts) ->
-	random:seed(now()),
+	random:seed(os:timestamp()),
 	{cowboy_rest, Req, Opts}.
 
 allowed_methods(Req, State) ->
@@ -57,13 +57,13 @@ create_paste(Req, State) ->
 paste_html(Req, index) ->
 	{read_file("index.html"), Req, index};
 paste_html(Req, Paste) ->
-	#{lang := Lang} = cowboy_req:match_qs([lang], Req),
+	#{lang := Lang} = cowboy_req:match_qs([{lang, [], plain}], Req),
 	{format_html(Paste, Lang), Req, Paste}.
 
 paste_text(Req, index) ->
 	{read_file("index.txt"), Req, index};
 paste_text(Req, Paste) ->
-	#{lang := Lang} = cowboy_req:match_qs([lang], Req),
+	#{lang := Lang} = cowboy_req:match_qs([{lang, [], plain}], Req),
 	{format_text(Paste, Lang), Req, Paste}.
 
 % Private