Project files were not following the clang-format style. For people
using IDEs were clang-format is always run after a save this would
cause unwanted changes.
This commit only applies "clang-format -i" to files.
* Add value_type to span
Currently I'm working on project which involves a lot of `span`s and mocking via Google Mock. Unfortunately a lot of standard matchers requires `value_type` type definition inside container which `gsl::span` lacks.
This pull request add `value_type` type definition inside `gsl::span`
* Strip cv from value_type of span and span_iterator
* Nest "gsl" directory inside a new "include" directory.
* Cleanup the _MSC_VER conditionals a bit; use constexpr on VS2017+.
* Don't #define noexcept on non-Microsoft implementations.
* Workaround VS2017 bug in multi_span. (Also implement == and != for static_bounds_dynamic_range_t because I'm an EoP semantic soundness snob.)
Fixes#441.
