Imports of cfssl-scan command

PathSynopsis
flagPackage flag implements command-line flag parsing.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
github.com/cloudflare/cfssl/cliPackage cli provides the template for adding new cfssl commands
github.com/cloudflare/cfssl/cli/scan
github.com/cloudflare/cfssl/configPackage config contains the configuration logic for CFSSL.
osPackage os provides a platform-independent interface to operating system functionality.
timePackage time provides functionality for measuring and displaying time.