This adds the `-console` command-line option (for Win32 only) so the
game can spawn an attached console window which will contain all console
output.
This is to make it easier for people to debug on Windows systems.
Otherwise, the only way to get console output would be to either compile
the application as a console app (i.e. switch the subsystem to console)
- which is undesirable for regular users as this makes it so a console
is always spawned even when unwanted - or launch the game with shell
arguments that make it so output is redirected to a file.
As a result, color checking support is factored out of vlog_init() into
its own function, even though we don't support colors on Windows.
They weren't ever being used, and nobody really ever uses the return
value from the printf family of functions anyway. They return how many
bytes were actually printed, but if it's less than you expected then
there's not much you can really do about them. Also the vlog_* functions
were computing them inaccurately because I only set the return value to
the return value of vprintf when there's other print functions being
called, but regardless there's no reason to have a return value here
anyway.
`-forcecolor` will force color to be on. `-nocolor` will force color to
be off.
And just because I'm a nice person, I've also added British versions of
those flags. As a treat.
This includes the bold as well.
INFO is just default, WARN is yellow, ERROR is red.
We try to automatically detect if the output is a TTY (and thus supports
colors), and don't emit colors if so. Windows 10 supports ANSI color
codes starting with a specific build, but we don't care to emit whatever
garbage Microsoft invented for builds older than that.
