Multi FS Support

- Reviving PR 191, to make FileSystem creation off actual path
 - Streamline all filesystem access to HoodieTableMetaClient
 - Hadoop Conf from Spark Context serialized & passed to executor code too
 - Pick up env vars prefixed with HOODIE_ENV_ into Configuration object
 - Cleanup usage of FSUtils.getFS, piggybacking off HoodieTableMetaClient.getFS
 - Adding s3a to supported schemes & support escaping "." in env vars
 - Tests use HoodieTestUtils.getDefaultHadoopConf

hoodie-common/src/main/java/com/uber/hoodie/avro/MercifulJsonConverter.java

@@ -77,7 +77,7 @@ public class MercifulJsonConverter {
     switch (schema.getType()) {
       case BOOLEAN:
         if (value instanceof Boolean) {
-          return (Boolean) value;
+          return value;
         }
         break;
       case DOUBLE: