Build System: Enable python3 compatibility.

* Consistently use spaces in rest-api-templates/asterisk_processor.py.
* Exclude third-party from docs/full-en_US.xml.
* Add docs/full-en_US.xml to .gitignore.
* Use list() to convert python3 view.
* Use python3 print function.
* Replace cmp() with equivalent equation.
* Replace reference to out of scope subtype variable with name
  parameter.
* Use unescaping triple bracket notation in mustache templates where
  needed.  This causes behavior of Python2 to be maintained when using
  Python3.
* Fix references to has_websocket / is_websocket in
  res_ari_resource.c.mustache.
* Update calculation of has_websocket to use any().
* Use unicode mode for writing output file in transform.py.
* Replace 'from swagger_model import *' with explicit import of required
  symbols.

I have not tested spandspflow2pcap.py or voicemailpwcheck.py, only the
print syntax has been fixed.

Change-Id: If5c5b556a2800d41a3e2cfef080ac2e151178c33

contrib/scripts/refcounter.py

@@ -18,6 +18,7 @@
  Matt Jordan <mjordan@digium.com>
 """
 
+from __future__ import print_function
 import sys
 import os
 
@@ -35,8 +36,8 @@ def parse_line(line):
     """
     tokens = line.strip().split(',', 7)
     if len(tokens) < 8:
-        print "ERROR: ref debug line '%s' contains fewer tokens than " \
-              "expected: %d" % (line.strip(), len(tokens))
+        print("ERROR: ref debug line '%s' contains fewer tokens than "
+              "expected: %d" % (line.strip(), len(tokens)))
         return None
 
     processed_line = {'addr': tokens[0],
@@ -142,7 +143,7 @@ def process_file(options):
                 del current_objects[obj]
 
     if options.leaks:
-        for key, lines in current_objects.iteritems():
+        for (key, lines) in current_objects.items():
             leaked_objects.append((key, lines))
     return (finished_objects, invalid_objects, leaked_objects, skewed_objects)
 
@@ -156,13 +157,13 @@ def print_objects(objects, prefix=""):
             this object
     """
 
-    print "======== %s Objects ========" % prefix
-    print "\n"
+    print("======== %s Objects ========" % prefix)
+    print("\n")
     for obj in objects:
-        print "==== %s Object %s history ====" % (prefix, obj[0])
+        print("==== %s Object %s history ====" % (prefix, obj[0]))
         for line in obj[1]['log']:
-            print line
-        print "\n"
+            print(line)
+        print("\n")
 
 
 def main(argv=None):
@@ -198,11 +199,11 @@ def main(argv=None):
 
     if not options.invalid and not options.leaks and not options.normal \
             and not options.skewed:
-        print >>sys.stderr, "All options disabled"
+        print("All options disabled", file=sys.stderr)
         return -1
 
     if not os.path.isfile(options.filepath):
-        print >>sys.stderr, "File not found: %s" % options.filepath
+        print("File not found: %s" % options.filepath, file=sys.stderr)
         return -1
 
     try:
@@ -227,7 +228,7 @@ def main(argv=None):
             print_objects(finished_objects, "Finalized")
 
     except (KeyboardInterrupt, SystemExit, IOError):
-        print >>sys.stderr, "File processing cancelled"
+        print("File processing cancelled", file=sys.stderr)
         return -1
 
     return ret_code