Handle writing a text node > 4000 characters to the db.
Right now, the postgres db can only handle a text node of 4000 characters. Currently we break calls to DBSAXNode.writeChildNodeToDB into 4000 char data chunks in several places in the code. However, there are some places where the data is not checked or chunked.
We need to move the chunking into the writeChildNodeToDB method, so it is taken care of centrally.