Add support for pre/post-apply/delete actions about stack_master HOT 1 OPEN

Thanks for writing this up @samuelsuarezsanchez!

I like the proposal :)

Here's some feedback:

• consider grouping all the "command hooks" under hooks or command_hooks instead of directly under the template name.
• an extension would be to support all/other commands other than apply and delete.
• consider renaming the actions directory to hooks or command_hooks.
• depending on use case, it may be preferable to always execute the post_<command> hooks regardless if the exit status of the pre_<command> hooks. In this case, a "command status" parameter is passed to the post hooks. For example, the post hooks could be used for some cleanup of the pre hooks that you always want to run.
• should post command hooks be executed if the command fails?

To be clear, I'm not suggesting increasing the scope of this proposal, just some things to think about so it can be extended in the future :)

from stack_master.