Clarify equalities a bit
Clarify empty lists & other list operations
Add some nil exposition
Leave out vec nil for now
Clarify keywords, symbols, maps, sets
Clarify wording in maps
Take pity and clarify higher-order fns a bit
Gitignore lein-repl-history
Merge branch 'master' into answered

Conflicts:
	src/koans/01_equalities.clj
	src/koans/02_lists.clj
	src/koans/03_vectors.clj
	src/koans/04_sets.clj
	src/koans/05_maps.clj
	src/koans/06_functions.clj
Finished koans!