run all images through optipng

ran `optipng -o7 images/**/*.png`

saved liked 6k overall, but hey, that's less to be inlined in the css
```bash
osmith osmith-ubuntu | Tue Oct 14 at 15:47:05 | git master
/home/osmith/dev/vui/valence-ui-icons/images ~ du -b
12464	./other
13192	./actions
5743	./properties
41057	./files
76552	.
```
```bash
osmith osmith-ubuntu | Tue Oct 14 at 15:46:57 | git minify-images
/home/osmith/dev/vui/valence-ui-icons/images ~ du -b
12347	./other
12298	./actions
5432	./properties
35137	./files
69310	.
```