CopyDir copies a directory and all of its contents to the destination directory.

CopyFile copies a file from a source to a destination.

Critical will print a message to os.Stderr unless DEBUG has been set, in which case panic will be called instead.

IsVersion returns whether str is a valid version number.

JoinErrors concatenates the elements of errs to create a single error.

TempDir joins the provided directories and prefixes them with the Sia testing directory.

VersionCmp returns an int indicating the difference between a and b.

Version is the current version of siad.

SiaTestingDir is the directory that contains all of the files and folders created during testing.