build+ci: switch to python3
Also in this commit:
* Sync CI scripts with other projects
* Sync sphinx_build waf tool with ndn-cxx
* Modernize docs/conf.py
* Replace redmine_issue extension with sphinx.ext.extlinks
* Fix typo in docs/doxygen.conf.in
* Improve README.md
Refs: #5095
Change-Id: Iee05500f907442dd7cb3e41bd613beef7461dab4
diff --git a/waf b/waf
index 7ceee16..a1c5c96 100755
--- a/waf
+++ b/waf
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
# encoding: latin-1
# Thomas Nagy, 2005-2018
#