Misc...

### summary 

- Some headers are already renamed
  - 4835310 Remove unnecessary header, see 5adcb5b
- `equal_to` v.s. `boost_tuple_iterator`
  - 5f416e2 Use category_of to get correct iterator category.
  - 7a7b225 Add boost_tuple_iterator_identity to compare iterator correctly.
- Because there is no documents and tests for `type_traits::ice_and`, use `mpl::and_` instead.
  - bd5ce92 Replace type_traits::ice_and with well documented mpl::and_
- C++11 constexpr v.s. C++14 constexpr
  - a7e9bb2 Fix to meet constexpr requirements
- from svn.boost.org
  - 20ee8d1 Fix missing includes, close ticket [#8457](https://svn.boost.org/trac/boost/ticket/8457).
  - ff56bea Remove use of `boost::blank`, close [#8622](https://svn.boost.org/trac/boost/ticket/8622)

Tested under x86_64-linux-gnu with GCC 4.9.1/Clang 3.5.0/GCC 4.4.7 (both of C++11/C++98 mode).