Cosmetic, comment and text cleanups

* functions
* stack.sh
* stackrc
* unstack.sh

A recent commit to stack.sh broke the RST formatting done by shocco to
produce the HTML-formatted files on devstack.org.  A bunch of comment
and spacing fixes were done (ala pep8 if there were such a thing for
shell scripts).

The only non-comment changes made were to the content of some error
messages.

Fixes bug 1042271

Change-Id: Id1c74cf25c03c4f18ed741f8026e36b0d4a598dd
diff --git a/unstack.sh b/unstack.sh
index 17752a8..e73cc2d 100755
--- a/unstack.sh
+++ b/unstack.sh
@@ -6,7 +6,7 @@
 # mysql and rabbit are left running as OpenStack code refreshes
 # do not require them to be restarted.
 #
-# Stop all processes by setting UNSTACK_ALL or specifying ``--all``
+# Stop all processes by setting ``UNSTACK_ALL`` or specifying ``--all``
 # on the command line
 
 # Keep track of the current devstack directory.