Revert addition of feature macros from other headers per latest SD-6.
2015-05-02 Edward Smith-Rowland <3dw4rd@verizon.net>
Revert addition of feature macros from other headers per latest SD-6.
* include/experimental/deque: Remove feature-test macro.
* include/experimental/forward_list: Ditto.
* include/experimental/list: Ditto.
* include/experimental/map: Ditto.
* include/experimental/set: Ditto.
* include/experimental/string: Ditto.
* include/experimental/unordered_map: Ditto.
* include/experimental/unordered_set: Ditto.
From-SVN: r222722