xsd-fu: C++ OMEXMLMetadata template uses std::make_shared

Needed to work around a clang++/libc++ bug in the internal
implementation details of std::enable_shared_from_this.
cpp: color test compiles with clang libc++ istringstream
cpp: compat memory header includes boost/make_shared.hpp
merge develop -D org: PR 528 (Tile performance improvements for VMS and NDPI)
merge develop -D org: PR 857 (Initial support for Zeiss .lms files)
merge develop -D org: PR 858 (Initial support for Veeco AFM data)
merge develop -D org: PR 859 (Assorted metadata/tile parsing fixes)
merge develop -D org: PR 945 (cpp: bioformats: Add MetadataMap class for original metadata)
merge develop -D org: PR 948 (Updating Aperio ImageScope weblink (rebased onto develop))
merge develop -D org: PR 949 (C++ fixes to work around clang++/libc++ bugs)