initial implementation of RCFilePigStorage.
Load support for RCFilePigStorage
putNext() can handle converting Tuple to RCFile bytes.
remove TupleOutputFormat.
RCFileOutputFormat does not need to depend on protobuf-java classes.
columnMetadata is passed in as Text().
remove protobuf jar from usage example.
Merge remote branch 'upstream/master' into rcfile_pig_storage
empty field value should be null.
while checking super class (like TBase), the 
superclass should be loaded from the same class
loader as the user class. Otherwise the test might
fail since the until class (ThriftUtil) and the user
class might have come from different class loaders.
check if a user class is a protobuf or a thrift
with out requiring those packages. No need to
require Message.class while using a Thrift class.
Also use the right class loader to instantiate
superclass.
Merge pull request #222 from rangadi/classloader_for_user_class

Use the correct class loader with thrift/protobuf.
null key in a map should be tolerated. Pig and Thrift are ok with it.
Merge pull request #223 from rangadi/handle_null_key_in_a_map

Handle null keys in Thrift maps
change log for 3.0.1
Merge pull request #224 from rangadi/changes-3.0.1

change log for 3.0.1
subclass check was reverse
Merge pull request #225 from rangadi/fix_super_class_check

fix subclass check in MultiInputFormat
[maven-release-plugin] prepare release elephant-bird-3.0.1
[maven-release-plugin] prepare for next development iteration
Adds test for pig to thrift enum value conversion failure
Updates PigToProtobuf enum conversion failure checking to match that of PigToThrift