Merge "Build System: Enable python3 compatibility."

Makefile

contrib/scripts/refcounter.py

contrib/scripts/spandspflow2pcap.py

contrib/scripts/voicemailpwcheck.py

doc/.gitignore

rest-api-templates/api.wiki.mustache

rest-api-templates/ari_resource.h.mustache

rest-api-templates/asterisk_processor.py

rest-api-templates/make_ari_stubs.py

rest-api-templates/res_ari_resource.c.mustache

rest-api-templates/swagger_model.py

rest-api-templates/transform.py