[boost] [foreach][polygon][xpressive][bimap][ptr_container][gil][assign][typeof][msm] PRs for removing executable attribute for files

The following libraries still have PRs, which I have previously submitted, for removing the executable attribute for one or more files: foreach polygon xpressive bimap ptr_container gil assign typeof msm None of these PRs affect anything other than the file attribute, so no testing is needed AFAICS since no code changes. If the maintainers of the above libraries, or someone else with write access to these libraries, can merge the appropriate PR to 'develop', and then merge 'develop' to 'master', we can get rid of having any files with their executable attribute set in the next release.