Add more compilers to CI and increase FMT_PEDANTIC warning levels (#736)

* Add a _lot_ more warnings to FMT_PEDANTIC
Fix these warnings

* Add more compilers to CI
Fix (some) of the compiler errors with them

* Enable -Werror on CI
Increase warning level on MSVC when compiling with FMT_PEDANTIC

* Add VS 2013 and 2015 to Appveyor

* Fix Appveyor tests
Formatting

* Implement requested changes
Fix some of the MSVC warnings
Implement C++11 integer_sequence

* Reintroduce appveyor-build.py

* Remove ranges-test from tests

* Remove (some) explicit warning suppressions
Fix C++ standard setting in CI

* Remove (some) explicit warning suppressions
Fix C++ standard setting in CI

* Fix test builds with C++11

* Enable pedantic warnings on tests

* Fix warnings from edits to master

* Cleanups

* Add C++11 support to ranges.h
Re-enable ranges-test
Fix a Visual Studio error about function not returning a value in printf.h
Fix a bug in .travis.yml

include/fmt/format-inl.h

@@ -45,12 +45,6 @@
 # define FMT_CATCH(x) if (false)
 #endif
 
-#ifdef __GNUC__
-// Disable the warning about declaration shadowing because it affects too
-// many valid cases.
-# pragma GCC diagnostic ignored "-Wshadow"
-#endif
-
 #ifdef _MSC_VER
 # pragma warning(push)
 # pragma warning(disable: 4127)  // conditional expression is constant
@@ -71,9 +65,6 @@ inline fmt::internal::null<> strerror_s(char *, std::size_t, ...) {
 
 FMT_BEGIN_NAMESPACE
 
-FMT_FUNC format_error::~format_error() throw() {}
-FMT_FUNC system_error::~system_error() FMT_DTOR_NOEXCEPT {}
-
 namespace {
 
 #ifndef _MSC_VER