When loading jni libraries which used fbjni, such as writing like
this:
    System.loadLibrary("mylib");
there will be a crash said that
    NativeLoader has not been initialized.  To use standard native
    library loading, call NativeLoader.init(new SystemDelegate()).
Since NativeLoader is in package com.facebook.soloader:nativeloader,
which is hidden from the user, a user have to manually import this
module.

Some Java codes take an exception as a paramter (e.g.
`public void callFailed(Call call, IOException ioe)` in okhttp)
Make JXXExceptions public to save time.