Avoides the need to exactly duplicate features of ancestors.
Opens possibility to match on super-terms
with partially provided (overriden) features.
For example, suppose there's `typeParameterized(child: param)`
term which is extended by `classifier` and `methodSignature`.
Then it becomes possible to write a common rule for both terms,
matching on `typeParameterized(param=[Smth])`.
Macro table can extend another macro table. All prototype template
declarations are imported automatically.
The editor now substitutes default values when entering new
expand macro/constraint filling the slots provided by the prototype.
Expand macro does not require name.
Minor editor improvements.
The old expand/call constructs are to be replaced by these.
Expand macro constraint refers to a named prototype, which
is specified in a macro table for matching concept.
Call macro constraint refers directly to a macro template.
Contex parameters are to be retired and explicit
parameters to expand macro constraint are to be used instead.
ExpandMacroTemplate to be used for dispatching macro invocations
based on the concept of the specified node.
Prototype is an abstraction to be implemented by
specific templates.
Call macros are to be parameterized with logicals and other parameters.
To replace combined expand/call macros causing confusion.
Context parameters to be passed explicitly.
Fedor Isakov