[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/decnet/Kconfig

@@ -1,6 +1,29 @@
 #
 # DECnet configuration
 #
+config DECNET
+	tristate "DECnet Support"
+	---help---
+	  The DECnet networking protocol was used in many products made by
+	  Digital (now Compaq).  It provides reliable stream and sequenced
+	  packet communications over which run a variety of services similar
+	  to those which run over TCP/IP.
+
+	  To find some tools to use with the kernel layer support, please
+	  look at Patrick Caulfield's web site:
+	  <http://linux-decnet.sourceforge.net/>.
+
+	  More detailed documentation is available in
+	  <file:Documentation/networking/decnet.txt>.
+
+	  Be sure to say Y to "/proc file system support" and "Sysctl support"
+	  below when using DECnet, since you will need sysctl support to aid
+	  in configuration at run time.
+
+	  The DECnet code is also available as a module ( = code which can be
+	  inserted in and removed from the running kernel whenever you want).
+	  The module is called decnet.
+
 config DECNET_ROUTER
 	bool "DECnet: router support (EXPERIMENTAL)"
 	depends on DECNET && EXPERIMENTAL