Fix typos for stack.sh and lib of comments and message

Fix 10 comments and 1 message

stack.sh
  Certicate => Certificate (comment)
lib/stack
  Sentinal => Sentinel (comment)
lib/neutron-legacy
  overriden => overridden (comment)
  necesssary => necessary (comment)
  notifiy => notify (message)
  notifations => notifications (comment)
lib/rpc_backend
  orginal => original (comment)
  cofiguration => configuration (comment)
lib/stack
  confgured => configured (comment)
lib/swift
  additinal => additional (comment)
  calclution => calculation (comment)
  maximun => maximum (comment)

Change-Id: I3637388b67decb007cd49af9addecc654009559b
diff --git a/lib/swift b/lib/swift
index 3a8e80d..634d6cc 100644
--- a/lib/swift
+++ b/lib/swift
@@ -123,13 +123,13 @@
 # trace through the logs when looking for its use.
 SWIFT_LOG_TOKEN_LENGTH=${SWIFT_LOG_TOKEN_LENGTH:-12}
 
-# Set ``SWIFT_MAX_HEADER_SIZE`` to configure the maximun length of headers in
+# Set ``SWIFT_MAX_HEADER_SIZE`` to configure the maximum length of headers in
 # Swift API
 SWIFT_MAX_HEADER_SIZE=${SWIFT_MAX_HEADER_SIZE:-16384}
 
 # Set ``OBJECT_PORT_BASE``, ``CONTAINER_PORT_BASE``, ``ACCOUNT_PORT_BASE``
-# Port bases used in port number calclution for the service "nodes"
-# The specified port number will be used, the additinal ports calculated by
+# Port bases used in port number calculation for the service "nodes"
+# The specified port number will be used, the additional ports calculated by
 # base_port + node_num * 10
 OBJECT_PORT_BASE=${OBJECT_PORT_BASE:-6613}
 CONTAINER_PORT_BASE=${CONTAINER_PORT_BASE:-6611}