Optimize pictures with optipng and jpegoptim.

About 80 kiB of savings, so no huge improvement.

Just ran
```
function optALLthings() {
cd $1;
optipng -o9 *.png;
jpegoptim --strip-all *.jpg;
for dir in `ls -d */`;
do
	optALLthings $dir;
	cd ..;
done;
}
```
in my apps directory.

Also fixed some file permissions with that (they shouldn't be executable, should they …).