Configure checks fail to handle Boost::Date_Time:

configure: WARNING: boost/date_time/posix_time/posix_time.hpp: present but cannot be compiled
configure: WARNING: boost/date_time/posix_time/posix_time.hpp:     check for missing prerequisite headers?
configure: WARNING: boost/date_time/posix_time/posix_time.hpp: see the Autoconf documentation
configure: WARNING: boost/date_time/posix_time/posix_time.hpp:     section "Present But Cannot Be Compiled"
configure: WARNING: boost/date_time/posix_time/posix_time.hpp: proceeding with the compiler's result
checking for boost/date_time/posix_time/posix_time.hpp... no
configure: error: cannot find boost/date_time/posix_time/posix_time.hpp
*** Error code 1

