fltrator : added patch to made fltrator-landscape use the correct data directory.
fltrator : corrected an error with meta
fltrator : enhancement based on srhb suggestion
fltrator : add .desktop
fltrator : enanced the build file, based on suggestion of jtojnar & srhb
fltrator : use nativeBuildInput rather that buildInputs. suggested by jtojnar
fltrator : desktop file is now pointing to the specific binary, and has icon.
fltrator : deleted the manual unpack phase
