Edited get_command, display_prompt, and main
Edited get_command, display_prompt, and main

display_prompt: added getlogin and get hostname, added error checking
                from them

get_command: fixed the flag integer so it worked for spaces before
             the '|' or '&'

main: tried to add if branches for '||' and '&&' but neds fixing
      I am unsure how to check if something failed

gillianzliu/rshell,gillianzliu/rshell