Faster compile for newer Pis and wrappers around exit codes

[realies]

It would be faster to compile software with the -j4 parameter on make using multicore systems (Pi 2, 3). Checking if commands are successfully executed before continuing with the installation process will reduce unsuccessful installations due to errors.

PS: No need for forever, the server can be wrapped in a while true statement.

[lanceseidman]

Curious, if the server crashes, what makes it come back up as Forever would? Not quite sure what you mean, perhaps you can share more details.