Merge branch 'develop'

Merge branch 'develop'

Don't build numpy if there's no python version to target.

Merge branch 'develop'

Merge pull request boostorg#43 from Flast/patch-1

Fix a compile error with obsoleted details.

Merge pull request boostorg#49 from fatso83/develop

Add cygwin64 support to wrap_python.hpp

Merge pull request boostorg#40 from jwakely/issue-39

Python: Fix condition for make_setter overload.

Merge branch 'develop'

Merge pull request boostorg#13 from ax3l/fix-missingPlaceholderInclude

Fix Trac #10932 Missing Include: Bind Placeholders

Release 1.55.0

[SVN r86621]