`Scope` keyword is introduced to declare method visibility.
For that package format version is incremented to 1.4.
`Scope` attribute can have two possible values:
* `Session` - regular method that is accessible from anywhere in
the current execution session. This is the default if the
attribute is omitted;
* `Public` - accessible anywhere, both within the session and from
outside through the API call (i.e. it is an action in current
terminology).
It allows to declare static actions with the following syntax:
methodName:
Usage: Static
Scope: Public
For backward compatibility `Usage: Action` remains valid and
acceptable but it is deprecated for format versions > 1.3. An
exception is raised if both `Usage: Action` and `Scope: Session`
are specified.
Change-Id: I5a6d664d017d5ea99a5159d7eb2e111143c7b0a3
Partially-implements: blueprint static-actions