Crated a branch for the new IO code for Boost.DateTime.

svn path=/branches/date_time_io_rewrite/boost/date_time/; revision=62584
Preliminary changes and the initial version of the spirit-based formatter.

svn path=/branches/date_time_io_rewrite/boost/date_time/; revision=62591
Merged recent changes from trunk.

svn path=/branches/date_time_io_rewrite/boost/date_time/; revision=62850
Added support for facet-based formatting. Implemented a locale-based character code conversion and deprecated the old one.

svn path=/branches/date_time_io_rewrite/boost/date_time/; revision=62928