Extend `cgroup:` parsing to support values with spaces

consider the following example:
```
aaron@framework ~> cat /sys/fs/cgroup/system/some-daemon/cpu.max
200000 100000
```

maybe we could support a syntax like this?
```
service cgroup:cpu.max:'200000 100000',pids.max:1048576 /usr/bin/some-daemon
```

what do you think? 🤔