* eliminate one case where basic_print_context would copy a string into a fmt::basic_memory_buffer character by character instead of using fmt::basic_memory_buffer::append
* use detail::write instead of re-implementing it
* use to_unsigned to avoid signedness conversion warnings
* add forgotten template argument to make_format_args which made some uses of FMT_COMPILE not work anymore after 54daa0864a, add more elaborate test cases to compile-test as regression tests
* fix old-style cast which gcc on travis thankfully doesn't accept anymore
* hopefully last forgotten (void*)
rimathia