VS10 doesn't have ssize_t.
Simplify constexpr strlen
Add non-member to_string(basic_string_ref)
Remove unused flavor of find_first_not_of().
Rename detail namespace in string_view.hpp to string_view_detail
Add non-deducing (converting) comparison operator overloads.
Add char* overloads for stox().
Add const_pointer typedef.
Add config support for NOEXCEPT.
Add configuration support for defaulted/deleted functions with USE_DEFAULT_DELETE.
Test case for one of the converting comparisons.
Sprinkle some NOEXCEPT and defaulted/deleted functions.