transmission: Add apparmor profile
transmission: Add apparmor service dependency
TOR: add obfsproxy support by default for TOR bridges
Merge pull request #174 from wizeman/apparmor-transmission

transmission: Add apparmor profile
Omit GRUB if boot.loader.grub.device is set to "nodev"

If we only need to generate a GRUB boot menu, we don't need GRUB
itself.  This cuts 38 MiB from EC2 system closures (in particular
because it gets rid of the need for the 32-bit Glibc).
nixos-rebuild: Handle .version-suffix not being writable

Reported by @vcunat.