Tagging vms

[maxzinkus]

Add support for adding and removing, and storing/printing custom string tags on VMs.

[maxzinkus]

it's designed for a small number of tags, e.g. 0-10 per VM, so the tag add/remove is done using linear scans of the tag list for simplicity rather than a more efficient but complex batched binary search.

[idroz]

This works really well. What are your thoughts on disallowing special characters (e.g. non alphanumeric) in tag names.

For example, the following tag one, two is currently permitted, but is internally treated as a single entity, which might be confusing.

I can merge and add non-alphanumeric checks in a separate pull request.

[maxzinkus]

That's a really good idea. a-zA-Z0-9 and some separator characters (-, _, .) should be plenty.