Added leaf generator method to STreeCollection
Fixed README link to test module
Fixed a bug where unpickling an STree didn't create it with a _cache attribute
Updated version to 0.5.3
RE: Fixed a bug where unpickling an STree didn't create it with a _cache attribute
Updated version to 0.5.4
Fixed a bug with the EXPAND1 operator (?rule)
Python grammar now supports dict-comprehensions
Repharsed concepts in readme
Added methods: remove_kids_by_head, prune_by_head
Added the 'cache_grammar' option; Version is now 0.5.7
PlyPlus is Python3 compliant again, marked version 0.6.0
Be symmetrical in _cache removing/restoring

I.e. since it's an attribute of STree and we remove it from there when
pickling: also restore it there when unpickling.

Signed-off-by: Giel van Schijndel <me@mortis.eu>
Merge branch 'symmetric-pickle-cache-mod'