Add custom Pipe class, to overhaul task launching
Add custom Pipe class, to overhaul task launching

This allows us to maintain ownership over the pipe’s file descriptors,
so NSTask or NSFileHandle don’t prematurely close them.

0xced/Carthage,flovilmart/Carthage,0xced/Carthage,abbeycode/Carthage,erichoracek/Carthage,abbeycode/Carthage,erichoracek/Carthage,erichoracek/Carthage,NachoSoto/Carthage,abbeycode/Carthage,NachoSoto/Carthage,flovilmart/Carthage,NachoSoto/Carthage,0xced/Carthage,abbeycode/Carthage,flovilmart/Carthage,erichoracek/Carthage