* add forgotten template argument to make_format_args which made some uses of FMT_COMPILE not work anymore after 54daa086, 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*)

Change msvc version of clz & clzll to match __builtin_clz & _builtin_clzll

* Disable fallthrough attributes for the Intel compilers

On MacOS and Linux the Intel compilers may be identified as the
host compilers (Clang or GNU) but do not support the corresponding
compiler specific fallthrough attributes.

* Rearrange ifdef logic for excluding pre-C++17 fallthrough attributes

This puts Intel and PGI compilers into a separate group
and thus makes the intent and logic more obvious.

1. FMT_ALWAYS_INLINE should imply inline; otherwise, there might be
   linkage problems
2. Add specialization for MSVC (__forceinline)

* Add format_to_n overload that accepts FMT_COMPILE

* add FormatToNWithCompileMacro test into CompileTest
Co-authored-by: Dmitriy Kurkin <Dmitriy.Kurkin@itiviti.com>

* Fix variable size basic_memory_buffer colorization
* Fix an unused arguments warning on GCC that blocks the CI otherwise
* Ref #1842
* Ref #1593

The `fmt` package have been available for `build2` users for several version, see: https://cppget.org/fmt

This simply add the minimum instructions for making a `build2` project depend on it.

There are other ways to do it, but they need more understanding of `build2`.

Add formatters for chrono::time_point and helper overloads for localtime/gmtime(time_point)
Fixes #1819