* omitted test_mpl_ops for now
* made IndexSpecifierList a Mp11 sequence
* made nested *_type_list's and tag Mp11 sequences
* leftover MPL->Mp11 change
* removed Clang 5.0 -std=c++1z as not supported by Mp11
* replaced boost::mpl::na with void as default index specifier arg
* removed Clang 5.0 -std=c++1z as not supported by Mp11 (Drone)
* replaced elementary MPL TMP with Mp11/std
* replaced elementary MPL TMP with Mp11/std (tests)
* leftover MPL #include
* suppressed potential narrowing conversion warnings
* enabled macro to support old interface, plus restored and augmented test_mpl_ops
* removed secondary dependency to MPL thru Iterator
* optimized Jamfile.v2
* added conditional support for old definition of tag
* updated MPL support macro in tests
* updated docs
* stylistic
* updated "cxxstd" in libraries.json
* disabled test_serialization for Clang 3.5-3.6 due to lack of support from Boost.SmartPtr
* fixed previous
* removed no longer necessary workaround
* removed redundant dependencies
* updated test description
* Make the library modular usable.
* Put back removing qualified boostcpp tag. As we need it until the Jamroot removes the qualified tag.
* Switch to library requirements instead of source. As source puts extra source in install targets.
* Remove uses of BOOST_ROOT in Jamfiles.
* Add requires-b2 check to top-level build file.
* Bump B2 require to 5.2
* Update copyright dates.
* Move inter-lib dependencies to a project variable and into the build targets.
* Update build deps.
