high: parse: Implicit initial parameter list

Proposed new syntax: Implicit initial parameter list.

This adds support for a shorthand syntax when creating
primitives and nodes: Instead of explicitly writing

primitive foo Foo params foo-param=1

this is now accepted as equivalent:

primitive foo Foo foo-param=1

Same thing for nodes, this

node my-node kernel=3.17.2

is parsed as

node my-node attributes kernel=3.17.2

The XML->CIB parser is still the same, so when inspecting
the created CLI syntax, params will have been injected.

However, this should make the creation of new primitives
a bit cleaner.