Drafting Indentation Propagation.
'edn' is initialized at first non-whitespace node; added 'length' and 'move-to-node'.
whitespace removal in 'remove'; alias instead of referral
implemented identation-aware zipper modification.
added tests for new 'edn' and identation-aware zippers
Using lein-midje 3.1.1; extended CHANGES.md
Fixed Behaviour of some of the operations; added indentation-aware splice.