Improve init's debug printing.

+ Make prints of rc commands significantly more verbose. All commands
  will log all arguments, file/line number of the command, return value,
  and parent action which triggered the command.

init: command 'mount tmpfs tmpfs /mnt/obb mode=0755,gid=1000' action=init
      status=0 (/init.rc:89)
init: command 'setprop net.tcp.default_init_rwnd 60' action=boot status=0
      (/init.rc:403)

Change-Id: I5498c7258e4891706be4a12546df4231d14d86c4