Most TODOs from JS removed, various fixes

Removed hard-coded data in "writeFully" (adb-io-thread)
Renamed "readFully" -> "readStringFully" (adb-io-thread)
Changed atransport type to an opaque struct
Refactored the freeing of internal listeners (ECW)
that = this -> .bind(this) (ECW)
Stick libPath in context
Single arg to a runOnPeerThread call works