Add option to not to create mountdr

[kacerr]

In our case we handle creation of target mount directory somewhere else.
I would like this to be optional. Also i have set default value to true, so if you don't specifically disable mount directory creation it will behave in the same way as before.

[purpleidea]

Thanks for the patch. Here's some review:

• $manage_mount_directory = true # enable/disable creation of directory to mount into

Needs a trailing comma, and a new name. How about we called this option mkdir ?

Secondly, patch is good, but needs to turn off the other two references to ${long_name}. One is a mount require (turn that on or off with a ? operator or reverse the dependency to be a "before" on the file.) and the other spot is the actual mkdir exec which needs to be conditional, right?

Resquash this into a single commit, and test, and I'm happy to merge.

Cheers,
James