Added property tree library

svn path=/sandbox/libs/property_tree/; revision=2739
Added sandbox project

svn path=/sandbox/libs/property_tree/; revision=2740
Removed bool* result parameter from _d versions of get, get_own and get_child

svn path=/sandbox/boost/property_tree/; revision=2741
Fixed parsers using (now removed) extra bool parameter to get_d

svn path=/sandbox/boost/property_tree/; revision=2742
Added locale support to get functions and ptree_empty function. Updated docs accordingly.

svn path=/sandbox/boost/property_tree/; revision=2744
Added new example

svn path=/sandbox/libs/property_tree/; revision=2745
Added boost::optional support

svn path=/sandbox/libs/property_tree/; revision=2746
Fixed locale names in locale test

svn path=/sandbox/libs/property_tree/; revision=2747
Fixed makefile

svn path=/sandbox/libs/property_tree/; revision=2748
Updated docs for _o versions

svn path=/sandbox/boost/property_tree/; revision=2749
Small fix to docs

svn path=/sandbox/libs/property_tree/; revision=2750
Minor fix

svn path=/sandbox/boost/property_tree/; revision=2751
Minor fixes

svn path=/sandbox/libs/property_tree/; revision=2752
Modified dirs layout

svn path=/sandbox/boost/property_tree/; revision=2756
Modified files structure and added fwd delcarations for ptree

svn path=/sandbox/boost/property_tree/; revision=2757
Added policy-defined data type

svn path=/sandbox/boost/property_tree/; revision=2758
Added index.html to libs dir

svn path=/sandbox/libs/property_tree/; revision=2759
Added INFO grammar example

svn path=/sandbox/libs/property_tree/; revision=2760
Updated docs and tests

svn path=/sandbox/libs/property_tree/; revision=2761
Updated examples and docs

svn path=/sandbox/libs/property_tree/; revision=2762