package: pin "readable-stream" to any v1.0.x
index: use the "readable-stream" copy of Writable

Never use the core version. This gives us more control and
less guess work / compat hacks.
index: emit "close" after setting `_closed`

This makes more sense to me for some reason...
index: add a debug() call
package: tighten up the dependencies' versions
index: remove streams2 compat hack
src: use `NanDisposePersistent()`
index: abort write() call if `_close` is set

Fixes #28.
Closes #29.
History: match `git changelog` output
v0.1.0