* Change version tag and ClosestTag values to be ns-3.xx
* Fix string values to have the proper format
* Allow check-version to proceed even if git task is not present
* Remove git package requirement from Docker containers
* Create git_ns3_version_info task only when HAVE_NS3_REPO is defined
* Change tag glob from ns-3* to ns-3.[0-9]*
* Use version tag to make output consistent with waf --check-version
* Add a git tag to the tip of the branch before building
* Install git package before building
* Update ubuntu and fedora builds to install git package
