update feature removal schedule

- Remove the netifrc related items since netifrc is now a separate
  package.

- State that the features we are planning to remove will be removed
  in version 1.0.

- Clarify the last entry; we are refering to start-stop-daemon options.
devfs: explicitly mount /dev/shm with mode=1777

The current code relies on the tmpfs mount defaulting to 1777
permissions.  If it doesn't, things break badly.

This can come up when tmpfs is disabled in the kernel and ramfs
is being used instead (the kernel will alias tmpfs to ramfs).
The default permissions for ramfs is 0755.