[NET]: move config options out to individual protocols

Move the protocol specific config options out to the specific protocols.
With this change net/Kconfig now starts to become readable and serve as a
good basis for further re-structuring.

The menu structure is left almost intact, except that indention is
fixed in most cases. Most visible are the INET changes where several
"depends on INET" are replaced with a single ifdef INET / endif pair.

Several new files were created to accomplish this change - they are
small but serve the purpose that config options are now distributed
out where they belongs.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/unix/Kconfig

@@ -0,0 +1,21 @@
+#
+# Unix Domain Sockets
+#
+
+config UNIX
+	tristate "Unix domain sockets"
+	---help---
+	  If you say Y here, you will include support for Unix domain sockets;
+	  sockets are the standard Unix mechanism for establishing and
+	  accessing network connections.  Many commonly used programs such as
+	  the X Window system and syslog use these sockets even if your
+	  machine is not connected to any network.  Unless you are working on
+	  an embedded system or something similar, you therefore definitely
+	  want to say Y here.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called unix.  Note that several important services won't work
+	  correctly if you say M here and then neglect to load the module.
+
+	  Say Y unless you know what you are doing.
+