Published fragment Policy on util packages.

Stated simply, general util packages aren’t allowed because they tend to become dumping grounds. But, specifically targeted util packages with narrow, focused domains, are.

util/
    assetutil/
    cookieutil/
    cryptoutil/
    emailutil/
    jsonutil/
    maputil/
    passwordutil/
    ptrutil/
    randutil/
    signingutil/
    sliceutil/
    stringutil/
    testutil/
    timeutil/
    uuidutil/