Funcy

- support Python 3.6 officially
- fix deprecation warnings in Python 3.5 and 3.6

- added cheatsheet
- many fixes in docs
- documented post_processing()
- fixed (print|log)_* on non-function callables

- fixed 3+ argument map() in Python 3

- support Python 3.5 officially
- added group_values()
- fixed i?partition_by() for non-boolean extended mapper
- cleanups and optimizations in colls and seqs

- added i?tree_nodes()
- added (log|print)_iter_durations() to debug utils
- added lists support to get_in(), set_in() and update_in()
- single argument takewhile() and dropwhile()
- published iwhere(), ipluck(), ipluck_attr() and iinvoke()
- support retry() with list (not tuple) of errors (Zakhar Zibarov)
- changed µs to mks in time messages
- optimized update_in()

- added rcompose()
- added i?tree_leaves()
- added pluck_attr() (Marcus McCurdy)
- added set_in() and update_in()
- added get_in() (Swaroop)
- fixed bug with flatten() follow not passed deep