VTY: improve VTY prompt and make sure exit/end works everywhere

Some nodes below 'config' didn't have ournode_exit / ournode_end,
and thus were not able to properly perform this function.  exit should
always only go back one level, while end drops us back to ENABLE_NODE.

The prompt now represents the nesting level, and there's one consistent
space after the final prompt character (typically #).
7 files changed
tree: 8d5bc6573fbdbf00fc0c883743ccbfde9d805e7d
  1. hlrsync/
  2. linux-kernel/
  3. openbsc/
  4. wireshark/
  5. README