* Add --enable-build-version option to control build version feature
* Disable build version when --enable-build-version is not specified
* Update getting started tutorial to reflect the new build option
* 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
Changes
* Adds a new class named Version to the core module
* Adds a template file to the core module named version-defines.h.in
* Adds --PrintVersion and --version arguments to the CommandLine class.
* Creates a new waf tool which queries the local git repository and extracts build information from itCreate a waf task to extract version information from git repository