Allow clean silencing of support prompt

[Bottersnike]

As nice as the prompt is, there are some situations where it's really not appropriate. At current, the best way to silence it is something like

import io, sys
stdout = sys.stdout
sys.stdout = io.StringIO()
import pygame
sys.stdout = stdout
del stdout, io, sys

This patch would allow the user to define the PYGAME_HIDE_SUPPORT_PROMPT environment variable in which case importing pygame wouldn't print the extra two lines.

[illume]

No.

#542

[illume]

Thanks, and sorry.

[illume]

Stop spamming our repo.

…

On Wednesday, July 17, 2019, Julian ***@***.***> wrote: PygameSilent <https://pypi.org/project/pygamesilent/> is a new shim for PyGame that applies this workaround more easily than directly applying environment variables or overriding stdout at every point. — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#559?email_source=notifications&email_token=AAACKRPVPWJ4WR4SLLMPMXTP72NDBA5CNFSM4F3RINGKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD2C7QIQ#issuecomment-512096290>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAACKRKR5QFBVYNXANKTPXDP72NDBANCNFSM4F3RINGA> .