use a custom BulkShardProcessor in the IndexWriterProjector

the BulkShardProcessor will retry on failures due to a full
thread pool queue and block the .add() method.
add another test for BulkShardProcessor testing the failure case
autocreate indexes synchronously on bulk inserts
Id & PartitionName classes using BytesRef now instead of String

this avoids unnecessary ByteRefs<->String conversions
added increasing delay to BulkShardProcessor retry logic
Merge pull request #924 from crate/s/copyfrom-mem-optimizations

Memory/Cpu optimizations, delay for retry, retry fixes
update elasticsearch to 1.2.1
fixup! update elasticsearch to 1.2.1
fixed BulkShardProcessor.add() blocking while retry is running
Merge branch 'copyfrom'
throw more detailed exception on insert input validation
updated changelog according to release of 0.39.1
fix activeRetries increment at BulkShardProcessor
fix the blob replication which broke with the es 1.2.1 update
implemented node network stats
documentation for node load metrics
implemented os expression on sys.nodes
added changelog entry for os expression on sys.nodes
implemented process expressions on sys.nodes
implemented max_open_file_descriptors expression