EFI support in SALI .master scripts

These changes allow for EFI support in sali master scripts.

I have put in a check in the initialization to see if we are in an EFI environment, and, if so, it sets a variable called $SALI_EFI. (This variable can also be set in the normal way a $SALI_* variable can be set, in which case there is no check).

I did this for two reasons. Most importantly for grub to install correctly it needs to be able to access the efivarfs so it can talk to the motherboard efi. This doesn't get auto mounted in the /sys directory. So if we are in an EFI environment our chroot setup needs to make sure that we have efivarfs mounted at /sys/firmware/efi/efivars . If $SALI_EFI is yes then the efivarfs is mounted at ${SALI_TARGET}/sys/firmware/efi/efivars when a chroot is created.

The second reason is for $SALI_EFI to be made available for scripting purposes. For example in my .master file I am currently using I have a slightly different disk layout made if $SALI_EFI is yes. I also have a completely different bootloader script run for EFI rather than for legacy. (I have one script that works to create workstations for either legacy or EFI).

I also wrote up an example post_bootloader script, but since I only am able to test code of ubuntu I am going to put it in another pull request because I am less confident of it. I will add details in that pull request.

There are a few different ways that this can be approached and I don't know if this completely gists with your style. However I hope this at least gives you information on what is needed for the EFI support in case you would like to do it in a different way. thanks

--dcl Dave LeFevre Purdue College of Science