Updates usage docs to reflect that ColorCollection.color_corrections and color_decisions return lists not tuples
Adds set_parentage method to ColorCollection
Adds ColorCollection merging documentation
Tests for and bugfix of ColorCorrection.has_sat and has_sop
Adds testing for ColorCollection child attributes and methods
Adds tests for setting ColorCollection.color_corrections and color_decisions
Bug fixes for setting file_in attributes
Also fixes the merging Collections with duplicates
Minor docs fix for usage of Collection
Merging Collections tests- back to 100%
Better headings in usage docs