[boost] [1.35.0][conversion] Failure to merge trunk changes to release branch

A number of failures for release branch testing of the conversion library were the result of changes to trunk that were not also merged into the release branch. Developers need to remember to merge changes into branches/release if the changes are to go in the 1.35.0 release. To speed testing, I've now done that for the conversion library. But, really, this is something individual developers need to take responsibility for. --Beman