on debian root= can by set to hfs or /dev/nfs in this case is analogue to rootfstype=nfs,
so follow this logic.

fixed bug if no mnt options specified (as part of nfsroot after server:path spec), nfsroot was
used as mountoption too, which caused mount command to fail.
Merge branch 'master' of https://github.com/xbianonpi/xbian-initramfs
Corrected a substitution typo and changed percentages for splash ...