CB-5585: Fixed hanging process stuck in terminal, will also help fix oth...

CB-5585: Fixed hanging process stuck in terminal, will also help fix other projects like grunt-cordovacli and generator-cordovacli because other commands are expected to run after 'cordova emulate'. 

Solution:
The problem was that when a child process is spawned the it runs another script which spawns more child processes. I tested out run.js and it terminates successfully after execution but the problem was emulator.js . stdout and stderr will have to go to a files because we need to redirect output so its not blocking the terminal or waiting for other child processes to finish.