Go to zero button

Button to return machine to working (G92) coorindates 0,0,0.  USE WITH CAUTION.  Do not run after a reset.
Immediate pause

Use grbl ! and ~ commands to immediately pause and unpause the machine.  This skips ahead of any queued commands or commands cached on the grbl controller.  Also add spacebar pause.
Merge branch 'daemon' into grblweb-mod
Merge branch 'gotozero' into grblweb-mod
Fixed return to zero command
Merge branch 'gotozero' into grblweb-mod
Improved init script

The init script now really works no matter what user you choose.  Also the script was modified so server.js no longer needs to know the absolute path where grblweb is installed.  Config file and server.js changed back to the original setup using ./i as the path for static webserver files.