Merge root index file.

svn path=/branches/release/libs/type_erasure/; revision=84413
Merge index note and redirect for type erasure.

svn path=/branches/release/boost/type_erasure/; revision=84438
Merge [81027] from the trunk.

svn path=/branches/release/boost/type_erasure/; revision=84442
Merge libraries.htm update.

svn path=/branches/release/libs/type_erasure/; revision=84504
Merge [84506] from trunk: Document that constructors initialize enable_shared_from_this. Fixes #8573.

svn path=/branches/release/boost/type_erasure/; revision=84507
merge [83504] from trunk

svn path=/branches/release/boost/type_erasure/; revision=84525