v2.0.0 Grounding Improvement

[dyumanaditya]

In this PR the grounding process in PyReason will change. After this, we will release PyReason v2.0.0, where rules can be input in text format, making the YAMLs obsolete.

• Change grounding process to loop through all possible variables and not just neighbors. This will allow for more complex rules.
• Add node/edge rule distinction. pred(x)<-pred1(y,x), pred2(y,z) is different from pred(x,y)<-pred1(y,x), pred2(y,z). This should be reflected in the YAMLs as well
• Add bound parser to rule parser so that we can pass in bounds in text rules
• Add annotation function parser to rule parser
• Read rules from text file
• Add comments for text file with # and remove any blank lines
• Add threshold class for text based rules
• Change all examples and documentation to support new rule format. We no longer support target_criteria
• Add tests to python workflow
• Immediate rules sorting inside rule parser
• More flexible annotation functions that don't require modification of interpretation.py
• Model class for pyreason instead of global variables. Include functions such as model.summary() after reasoning.
• Input graph from networkx format as requested by Read Graph from NetworkX Graph object #9
• Input facts and rules as object Expose YAML object class in SDK #10
• Remove diffuse.py and command line support
• Allow ground rules with setting
• Make interpretations static through rules
• Return interpretations as a dict instead of class object
• Add support for multi di-graph
• Look into prev_l and prev_u in interval class
• If there's no change to an interpretation (same rule firing) it should be added to the trace
• Look into not checking for whether variable is __source in edge rule node clauses

Currently PyReason loops through all nodes and edges and checks for neighbor groundings. This is inflexible with rules such as pred(x)<-pred1(y,x), pred2(y,z) where y will be replaced by the neighbors of x--where in reality this should be any other node (except in the case of a node clause, then the groundings are the neighbors).

[dyumanaditya]

TODO: Fix issue with all nodes not having list of reversed neighbors