Added "unzip" to the build dependencies
Merge pull request #152 from jaltek/patch-1

Added "unzip" to the build dependencies
Remove mtools-host as it's unused and can cause build failures
Fixes #169
Merge pull request #170 from lurch/remove_mtools-host

Remove mtools-host as it's unused and can cause build failures
Update README.md

Clarify that Custom OSes won't work if you're using NOOBS to run multiple OSes.