ports: Add quake2 port (+two years of banan-os!)

This patch adds software rendered quake2 port. I was supposted to push
this as two days ago as two years of banan-os, but I was too sick to do
any programming.

ports/quake2/build.sh

@@ -0,0 +1,36 @@
+#!/bin/bash ../install.sh
+
+NAME='quake2'
+VERSION='git'
+DOWNLOAD_URL="https://github.com/ozkl/quake2generic.git#a967e4f567a98941326fc7fe76eee5e52a04a633"
+
+configure() {
+	:
+}
+
+build() {
+	baseq2_tar=../baseq2.tar.gz
+	baseq2_hash=9660c306d9440ff7d534f165ae4a7f550b9e879d5190830953034ebda10e873a
+
+	if [ -f $baseq2_tar ]; then
+		if ! echo "$baseq2_hash $baseq2_tar" | sha256sum --check >/dev/null; then
+			rm $baseq2_tar
+		fi
+	fi
+	if [ ! -f $baseq2_tar ]; then
+		wget https://bananymous.com/files/baseq2.tar.gz -O $baseq2_tar || exit 1
+	fi
+	if ! echo "$baseq2_hash $baseq2_tar" | sha256sum --check >/dev/null; then
+		echo "File hash does not match" >&2
+		exit 1
+	fi
+	make -j$(nproc) || exit 1
+}
+
+install() {
+	cp build/quake2 "${BANAN_SYSROOT}/bin/" || exit 1
+
+	baseq2_tar=$(realpath ../baseq2.tar.gz || exit 1)
+	cd "$BANAN_SYSROOT/home/user/"
+	tar xf $baseq2_tar
+}