[CODEC-61] Base64.EncodeBase64() throws NegativeArraySizeException on large files.

Throws IllegalArgumentException when the input array needs an output array bigger than Integer.MAX_VALUE.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@618419 13f79535-47bb-0310-9956-ffa450edef68

Author: garydgregory