Constexpr String View (#254)
Constexpr String View (#254)

* Constexpr String View

Using eastl::string_view in a constexpr context causes a compile error

* Fix constexpr in VS 2015

Changed EA_CONSTEXPR to EA_CPP14_CONSTEXPR

electronicarts/EASTL,electronicarts/EASTL,electronicarts/EASTL