Upbge v0.3 release

[e2002e]

This is the current release with ssgi as discussed in #1746. This was written a while ago as an addon, and then got included directly into the C code, author made a build dedicated to this module and kindly gave me the patch.
Can be found at: https://n0451.gumroad.com/l/PgyXc

[e2002e]

Still there is a issue though, when refraction is activated, reflections disappear. I'm going to contact the author today.

[e2002e]

I'm reopening since it might be some time before eevee next, this is fully functional.
Stating the author, just like in standard eevee mode, an object cannot participate in reflections and in refractions.

[youle31]

Thanks for sharing! As lordloki said, we try to avoid conflicts with eevee sources and this patch should be available later in eevee next. But it's cool for the ones who want to try to build upbge 0.30 with your patch. Also, if someone wants to share experimental builds of it for windows/linux/mac, he can maybe ask lordloki to add it in upbge Mega folder in experimental or misc section