Comment 0 for bug 1023179

As discussed at UDS-Q, a simple cloud-config syntax improvement woudl be nice:

in multi-part input, currently, you can only overwrite entries in cloud-config. Ie, if one part has:
  run-cmd:
    - apt-get install foo
 and another has:
 run-cmd:
   - apt-get install bar

 Then whichever is later will overwrite the 'run-cmd'. I'd like to do something like:
 == part 1 ==
 run-cmd:
   - apt-get install foo
 == part 2 ==
 run-cmd+:
   - apt-get install bar

Ie, the '+' would indicate append to the list or dict. Also intend to add '-' to remove.