Merge from trunk

svn path=/branches/bcbboost/tools/build/v2/; revision=39533
Merge from trunk

svn path=/branches/bcbboost/tools/jam/; revision=39560
Merge from trunk

svn path=/branches/bcbboost/tools/build/v2/; revision=39594
Merge from trunk

svn path=/branches/bcbboost/tools/build/v2/; revision=39768
Merge from trunk

svn path=/branches/bcbboost/tools/build/v2/; revision=39987
Merge from trunk

svn path=/branches/bcbboost/tools/build/v2/; revision=49055
Merge from trunk

svn path=/branches/bcbboost/tools/build/v2/; revision=49100
Merge from trunk

svn path=/branches/bcbboost/tools/build/v2/; revision=49113