meta: add node-exit as dependency
main: work around node #3584
meta: remove support for node 0.8
stream: use native streams

changes to work around node issue #3584 require use of
node-exit package.  This is not supported on node 0.8, so
no longer using readable-stream package to support
node 0.8.
meta: update requested/required dependency versions
0.6.1