Build standalone ioq3ded, fix asset timeout (#16)

When specifying `BUILD_STANDALONE=1` for ioq3ded, the default `com_homepath`, `com_basegame`, and `com_gamename` change to foo/foobar, so this sets those explicitly to their previously default values. This can be exposed via option later to allow for custom games. This also fixes the short read timeout used by CopyAssets.

internal/util/net/http/http.go

@@ -10,7 +10,7 @@ import (
 
 func GetBody(url string) ([]byte, error) {
 	client := http.Client{
-		Timeout: 30 * time.Second,
+		Timeout: 5 * time.Minute,
 	}
 	resp, err := client.Get(url)
 	if err != nil {