replace ColumnarMetatdata with a dynamicproto
remove support for CountedMap (pig map support for protobufs)
remove misc.proto
Merge pull request #418 from rangadi/remove_protobufs

Replace ColumnarMetadata protobuf used in RCFile with dynamic protobuf, remove CountedMap for pig
Merge pull request #422 from ianoc/ianocBase64DecodePerf

Use signficantly faster base64 implementation
Don't copy the array before handing it for base64 decode