*  **Fix: Lazily initialize the response cache.** This avoids strict mode
    warnings when initializing OkHttp on Android‘s main thread.

 *  **Fix: Disable ALPN on Android 4.4.** That release of the feature was
    unstable and prone to native crashes in the underlying OpenSSL code.
 *  Fix: Don't send both `If-None-Match` and `If-Modified-Since` cache headers
    when both are applicable.
 *  Fix: Fail early when a port is out of range.