use util.inherits() from node core
feature: Support setting size of LRU-cache
updated contributors
Merge pull request #49 from ralphtheninja/util-inherits

use util.inherits() from node core
fix: check that UINT32_OPTION_VALUE is a Uint32
Merge pull request #50 from kesla/cache-options

feature: Support setting size of LRU-cache
test that open and close are idempotent
idempotent open and close, and emit _state as events
document state events
minor code style adjustments
adjust copyright & contributors
proper cleanup after idempotent test
minor c++ code reorg, move constructors out of .h
use util._extend instead of local variant
readme tweaks
change createIfMissing default to true
fix GitHub MD derpery
fix createIfMissing tests for defaults change
version bump for 0.5 @dev release
remove LevelUP components