efivar 0.22

This has some new things in it:

• various build fixes for several compilers
• hopefully getting SATA PMP IDs right
• Reworked makefiles
• better handling of device node numbers
• devices mounted at more than one path work now
• make -j works better now
• lots of device path fixes
• fixes to efivar -L
• better nvme handling in libefiboot
• efivar (and libefivar) will now work transparently with immutable efivarfs files.