Bump Boost version requirement to fix clang build failure

This fixes the clang compile time error that was originally reported
in https://svn.boost.org/trac/boost/ticket/6198.
Adjust Travis CI configuration to updated Boost version requirement

The Travis CI VM's run Ubuntu 12.04 (precise) which does not have a
recent enough Boost version.  Use the build-time options to include
upstream Boost versions in the source tree to work around this.