Add clean.sh

clean.sh gets rid of all residue of running DevStack except installed
packages and pip modules.

And it eradicates rabbitmq-server and ts erlang dependencies as well as
the other RPC backends and databases.

Change-Id: I2b9a251a0a151c012bae85a5a2f9c2f72e7700be
diff --git a/lib/swift b/lib/swift
index 5c4ceab..04a54c3 100644
--- a/lib/swift
+++ b/lib/swift
@@ -388,9 +388,11 @@
 # stop_swift() - Stop running processes (non-screen)
 function stop_swift() {
     # screen normally killed by unstack.sh
-    if type -p swift-init >/dev/null;then
+    if type -p swift-init >/dev/null; then
         swift-init --run-dir=${SWIFT_DATA_DIR}/run all stop || true
     fi
+    # Dump the proxy server
+    sudo pkill -f swift-proxy-server
 }
 
 # Restore xtrace