space2altgr

I had space → altgr working under xcape, but it has been deprecated in Ubuntu 18.04, so I switched to intercept and tried to make a minimal change to space2meta. I just changed all occurrences of LEFTMETA with RIGHTALT. It works for the Level3 keys that are not combining keys, but does not work for combining keys. I thought I'd mention this in case you could think of what else needs to be done for it to work with Level3 deadkeys. Thanks.