Making CouchDB accessible over HTTP (instead of HTTPS)

This introduces a new configuration setting `db.procotol`, whose value should be `http` or `https`. It defaults to `https`. The Cloudant client will not initialize if the protocol is not set to `https`.

It also makes the convenience container `whisk/couchdb` work over HTTP rather than HTTPS. The main motivation is to allow REST calls to such local CouchDB deployments (interestingly, the CouchDB Java API was apparently happily ignoring the invalid certificates the whole time).
diff --git a/tools/cli/wskadmin b/tools/cli/wskadmin
index b2cbf09..d7e9ba1 100755
--- a/tools/cli/wskadmin
+++ b/tools/cli/wskadmin
@@ -33,6 +33,7 @@
 import uuid
 
 DB_WHISK_AUTHS = 'DB_WHISK_AUTHS'
+DB_PROTOCOL    = 'DB_PROTOCOL'
 DB_HOST        = 'DB_HOST'
 DB_PORT        = 'DB_PORT'
 DB_USERNAME    = 'DB_USERNAME'
@@ -45,7 +46,7 @@
 
 def main():
     whiskprops = wskprop.importPropsIfAvailable(wskprop.propfile(os.getcwd()))
-    requiredprops = [ DB_WHISK_AUTHS, DB_HOST, DB_PORT, DB_USERNAME, DB_PASSWORD ]
+    requiredprops = [ DB_WHISK_AUTHS, DB_PROTOCOL, DB_HOST, DB_PORT, DB_USERNAME, DB_PASSWORD ]
     (valid, props, deferredInfo) = wskprop.checkRequiredProperties(requiredprops, whiskprops)
 
     exitCode = 0 if valid else 2
@@ -99,6 +100,7 @@
         return 2
 
 def createUserCmd(args, props):
+    protocol = props[DB_PROTOCOL]
     host     = props[DB_HOST]
     port     = props[DB_PORT]
     username = props[DB_USERNAME]
@@ -117,7 +119,8 @@
         'subject': subject
     }
 
-    url = 'https://%(host)s:%(port)s/%(database)s' % {
+    url = '%(protocol)s://%(host)s:%(port)s/%(database)s' % {
+        'protocol': protocol,
         'host'    : host,
         'port'    : port,
         'database': database
@@ -145,13 +148,15 @@
         return 1
 
 def getSubjecFromDb(args, props):
+    protocol = props[DB_PROTOCOL]
     host     = props[DB_HOST]
     port     = props[DB_PORT]
     username = props[DB_USERNAME]
     password = props[DB_PASSWORD]
     database = props[DB_WHISK_AUTHS]
 
-    url = 'https://%(host)s:%(port)s/%(database)s/%(subject)s' % {
+    url = '%(protocol)s://%(host)s:%(port)s/%(database)s/%(subject)s' % {
+        'protocol': protocol,
         'host'    : host,
         'port'    : port,
         'database': database,
@@ -170,6 +175,7 @@
         return (None, res)
 
 def deleteUserCmd(args, props):
+    protocol = props[DB_PROTOCOL]
     host     = props[DB_HOST]
     port     = props[DB_PORT]
     username = props[DB_USERNAME]
@@ -185,7 +191,8 @@
         print 'Failed to delete subject (%s)' % res.read().strip()
         return 1
 
-    url = 'https://%(host)s:%(port)s/%(database)s/%(subject)s?rev=%(rev)s' % {
+    url = '%(protocol)s://%(host)s:%(port)s/%(database)s/%(subject)s?rev=%(rev)s' % {
+        'protocol': protocol,
         'host'    : host,
         'port'    : port,
         'database': database,
@@ -205,6 +212,7 @@
         return 1
 
 def whoisUserCmd(args, props):
+    protocol = props[DB_PROTOCOL]
     host     = props[DB_HOST]
     port     = props[DB_PORT]
     username = props[DB_USERNAME]
@@ -212,7 +220,8 @@
     database = props[DB_WHISK_AUTHS]
     uuid     = args.uuid.split(':')[0]
 
-    url = 'https://%(host)s:%(port)s/%(database)s/_design/%(database)s/_view/uuids?key=["%(uuid)s"]' % {
+    url = '%(protocol)s://%(host)s:%(port)s/%(database)s/_design/%(database)s/_view/uuids?key=["%(uuid)s"]' % {
+        'protocol': protocol,
         'host'    : host,
         'port'    : port,
         'username': username,