Imports of package diff

PathSynopsis
cuelang.org/go/cuePackage cue is the main API for CUE evaluation.
cuelang.org/go/cue/astPackage ast declares the types used to represent syntax trees for CUE packages.
cuelang.org/go/cue/errorsPackage errors defines shared types for handling CUE errors.
cuelang.org/go/cue/formatPackage format implements standard formatting of CUE configurations.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
ioPackage io provides basic interfaces to I/O primitives.
strconvPackage strconv implements conversions to and from string representations of basic data types.