Fixed the handling of missing data in plan descriptions.

    1. Do not show rows that contain no data at all
    2. Use '-' instead of '?' for missing values
Merge pull request #3321 from pontusmelke/missing-data-in-plandescription

Fixed the handling of missing data in plan descriptions.
Moved CypherVersion from compiler to the Cypher top module
Move PlanDescription et al to the Cypher top-module
moving CypherException from compiler to top lovel module