@api-vendortag

[erunion]

This completely replaces the old concept of API capabilities with a new, more generalized and OAI-compatible @api-vendortag.

You write them exactly the same you did capabilities:

@api-vendorTag needs:someRequirement

…

@api-param:private status (enum, needs:someRequirement) - The status of the object.

You configure them the same way you would with <capabilities>, that's just now called <vendorTags>:

<vendorTags>
    <vendorTag name="needs:someRequirement" />
</vendorTags>

And using our generators, you can also filter on them the same way you would with the --capability argument, it's now just called --vendor_tag.

Resolves #148