Bumped the Autoconf build dependency to 2.68 (released 2010-09-22).
Imported the AX_CXX_COMPILE_STDCXX_11 macro from the Autoconf Archive.

Source: http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_11.html
Updated the build system for C++11 support and a Clang preference.
Imported a Doxygen configuration file template generated with:

    $ doxygen -g doc/doxygen/Doxyfile
Customized the Doxygen configuration file.
Imported a DOAP file for the project.
Converted the code base from C to C++.
Imported a basic README file and a TODO file placeholder.
Integrated with Travis CI for build status notifications.

See: http://about.travis-ci.org/docs/user/getting-started/
See: http://about.travis-ci.org/docs/user/build-configuration/
See: http://about.travis-ci.org/docs/user/languages/cpp/