Update core/src/main/java/com/orientechnologies/orient/core/serialization/serializer/record/string/ORecordSerializerSchemaAware2CSV.java

To solve issue : https://github.com/nuvolabase/orientdb/issues/1259, add protection for NPE
Update server/src/main/java/com/orientechnologies/orient/server/task/OCreateRecordDistributedTask.java

NPE protection. In distribute mode, when create record, server which sync record from other server, writeExternal/readExternal will be trigger to serialize the data from inputstream, at this time <ORecordVersion>version is null, throws NPE. After change, sync works fine on both servers. Not sure this is the best solution, please check 
Update server/src/main/java/com/orientechnologies/orient/server/task/OUpdateRecordDistributedTask.java

Same change to OCreateRecordDistributedTask.java
Merge pull request #1270 from henryzhao81/master

Distributed not working.