New port: devel/py-darts.util.lru

A LRUDict is basically a simple dictionary, which has a defined
maximum capacity, that may be supplied at construction time, or
modified at run-time via the capacity property:

cache = LRUDict(1)
cache.capacity

1

WWW: https://pypi.python.org/pypi/darts.util.lru

PR: 211047
Submitted by: Danilo G. Baio <dbaio@bsd.com.br>