move ifupdown2/* .

ifupdown2 code was one level deeper because ifupdown2 initially
had ifupdown2 and ifupdown2-addons as two separate packages.
Since they were combined into one package, it makes sense to
move all combined code under the top level directory

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>

README.rst

@@ -0,0 +1,74 @@
+python-ifupdown2
+================
+
+This package is a replacement for the debian ifupdown package.
+It is ifupdown re-written in python. It maintains the original ifupdown
+pluggable architecture and extends it further.
+
+The python-ifupdown2 package provides the infrastructure for
+parsing /etc/network/interfaces file, loading, scheduling and state
+management of interfaces.
+
+It dynamically loads python modules from /usr/share/ifupdownaddons.
+To remain compatible with other packages that depend on ifupdown,
+it also executes scripts under /etc/network/.
+To make the transition smoother, a python module under
+/usr/share/ifupdownaddons will override a script by the same name under
+/etc/network/.
+
+It publishes an interface object which is passed to all loadble python
+modules. For more details on adding a addon module, see the section on
+adding python modules.
+
+
+pluggable python modules:
+=========================
+Unlike original ifupdown, all interface configuration is moved to external
+python modules. That includes inet, inet6 and dhcp configurations.
+
+A set of default modules are included in the package.
+
+python-ifupdown2 expects a few things from the pluggable modules:
+- the module should implement a class by the same name
+- the interface object (class iface) and the operation to be performed is
+  passed to the modules
+- the python addon class should provide a few methods:
+	- run() : method to configure the interface.
+	- get_ops() : must return a list of operations it supports.
+		eg: 'pre-up', 'post-down'
+	- get_dependent_ifacenames() : must return a list of interfaces the
+	  interface is dependent on. This is used to build the dependency list
+	  for sorting and executing interfaces in dependency order.
+	- if the module supports -r option to ifquery, ie ability to construct the
+      ifaceobj from running state, it can optionally implement the
+      get_dependent_ifacenames_running() method, to return the list of
+      dependent interfaces derived from running state of the interface.
+      This is different from get_dependent_ifacenames() where the dependent
+      interfaces are derived from the interfaces config file (provided by the
+      user).
+
+Example: Address handling module /usr/share/ifupdownaddons/address.py
+
+
+build
+=====
+- get source
+
+- install build dependencies:
+    apt-get install python-stdeb
+    apt-get install python-docutils
+
+- cd <python-ifupdown2 sourcedir> && ./build.sh
+
+  (generates python-ifupdown2-<ver>.deb)
+
+install
+=======
+
+- remove existing ifupdown package
+  dpkg -r ifupdown
+
+- install python-ifupdown2 using `dpkg -i`
+
+- or install from deb
+    dpkg -i python-ifupdown2-<ver>.deb