"#include" <spdlog/.*> instead of "spdlog/.*"

The meaning of using quotes to #include is implementation defined, so it
may or not may be what we want. At least POSIX
(https://pubs.opengroup.org/onlinepubs/9699919799/utilities/c99.html)
says: "headers whose names are enclosed in double-quotes ( "" ) shall be
searched for first in the directory of the file with the #include line",
so not what we want since "spdlog" ends up twice in the path.

Correctly guard SetHandleInformation API call

`__cplusplus_winrt` only detected C++/CX (which can be used without compiling for UWP, SetHandleInformation would be available in those cases), and did not detect native UWP C++. This patch fixes that by using the WINAPI_FAMILY_PARTITION macro in the Windows SDK headers in the same way those headers remove SetHandleInformation in UWP builds.

Improve log macros

improve systemd journald support

Previously, the logger name was effectively lost. There were two choices
on how to add it:

- Via a formatter, which would mean that `journalctl` would not be able
to filter against that. That would be suboptimal.

- As a "syslog identifier". This means that `journalctl` will, by
default, stop showing the daemon's executable name and replace that via
the logger name. The PID is still shown, and if one would like to go
back to the previous behavior, it is still possible via `journalctl -o
with-unit`.

I think that the second option is strictly better than the first one.

fixes #1289