Review, improve and document the static files handler

Changes include:

 *  Much simplified route configuration.

 *  Etag generation is now enabled by default.

 *  Web mimetypes are now detected by default. A bigger list of
    mimetypes can be detected without any additional library.

 *  Mimetypes can no longer be specified as a list. Copying this
    list for new connections is too costy. You can easily convert
    it into a function and pass that function to the handler instead.

 *  You can however specify a single hardcoded mimetype. Mostly
    useful when serving a single file, like an index.html file,
    to avoid extra operations.

 *  Specifying a path as a list of tokens is not possible anymore.
    Use either a binary or a string.

 *  Using a private directory will not work if the application
    was not started properly. Cowboy will not attempt to find
    the location of this directory if the VM doesn't know it,
    as this caused issues in some setups.

 *  Overall the code has been much simplified and clarified,
    and of course has now been documented.

2 files changed, 35 insertions, 0 deletions

diff --git a/manual/cowboy_static.md b/manual/cowboy_static.md
new file mode 100644
index 0000000..01aa2bf
--- /dev/null
+++ b/manual/cowboy_static.md
@@ -0,0 +1,34 @@
+cowboy_static
+=============
+
+The `cowboy_static` module implements file serving capabilities
+by using the REST semantics provided by `cowboy_rest`.
+
+Types
+-----
+
+### opts() = {priv_file, atom(), string() | binary()}
+	| {priv_file, atom(), string() | binary(), extra()}
+	| {file, string() | binary()}
+	| {file, string() | binary(), extra()}
+	| {priv_dir, atom(), string() | binary()}
+	| {priv_dir, atom(), string() | binary(), extra()}
+	| {dir, atom(), string() | binary()}
+	| {dir, atom(), string() | binary(), extra()}
+
+> Configuration for the static handler.
+>
+> The handler can be configured for sending either one file or
+> a directory (including its subdirectories).
+>
+> Extra options allow you to define how the etag should be calculated
+> and how the mimetype of files should be detected. They are defined
+> as follow, but do note that these types are not exported, only the
+> `opts/0` type is public.
+
+### extra() = [extra_etag() | extra_mimetypes()]
+
+### extra_etag() = {etag, module(), function()} | {etag, false}
+
+### extra_mimetypes() = {mimetypes, module(), function()}
+	| {mimetypes, binary() | {binary(), binary(), [{binary(), binary()}]}}
diff --git a/manual/toc.md b/manual/toc.md
index d05696e..3bcb875 100644
--- a/manual/toc.md
+++ b/manual/toc.md
@@ -13,6 +13,7 @@ The function reference documents the public interface of Cowboy.
  *  [cowboy_req](cowboy_req.md)
  *  [cowboy_rest](cowboy_rest.md)
  *  [cowboy_router](cowboy_router.md)
+ *  [cowboy_static](cowboy_static.md)
  *  [cowboy_sub_protocol](cowboy_sub_protocol.md)
  *  [cowboy_websocket](cowboy_websocket.md)
  *  [cowboy_websocket_handler](cowboy_websocket_handler.md)