gcc 10 no longer lets you get away with not externing global variables in header files. This adds the necessary extern and adds defines in appropriate c files
Using the key `emupath` on a boot entry will load the selected emuMMC.
This can also be forced by using the correct boot cfg storage bit and writing the path at the emummc path offset. Check readme for these.
This can only be used if the emuMMC was created via Nyx. because of the raw_based and file_based files that have emuMMC info.
(emupath=emuMMC/RAW1, emupath=emuMMC/SD00, etc)
