Updated vision and architecture

In this release we have completely revised the vision and architecture of Spline. Starting from 0.4 release Spline has begun its journey from being a simple Spark-only lineage tracking tool towards a more generic concept - a cross-framework data lineage tracking solution. The new vision covers much broader aspects of lineage tacking, including (at certain extent) real-time monitoring, errors tracking, impact analysis and many more. Spline version 0.4.0 is the first version of that “new” Spline. It doesn’t contain any brand-new features so far comparing to Spline 0.3.9, but it rather provides a brand-new background and architecture.

See Spline 0.4.0 release notes for details.