Imports of codegen command

PathSynopsis
bytesPackage bytes implements functions for the manipulation of byte slices.
embedPackage embed provides access to files embedded in the running Go program.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
go/formatPackage format implements standard formatting of Go source.
logPackage log implements a simple logging package.
osPackage os provides a platform-independent interface to operating system functionality.
pathPackage path implements utility routines for manipulating slash-separated paths.
sortPackage sort provides primitives for sorting slices and user-defined collections.
text/templatePackage template implements data-driven templates for generating textual output.