This commit was manufactured by cvs2svn to create branch 'RC_1_31_0'.

svn path=/branches/RC_1_31_0/boost/boost/variant/; revision=21427
Merged fix for CWPro workaround update from trunk to branch.

svn path=/branches/RC_1_31_0/boost/boost/variant/; revision=21655
Merged additional compiler-version updates from trunk to branch.

svn path=/branches/RC_1_31_0/boost/boost/variant/; revision=21712