Allow other characters for LINES TERMINATED BY

LINES TERMINATED BY only supports newline '\n' right now.

It would be nice to loosen this constraint and allow other characters.

This limitation seems to be hardcoded here:
https://github.com/apache/hive/blob/trunk/ql/src/java/org/apache/hadoop/hive/ql/parse/BaseSemanticAnalyzer.java#L171

The DDL Definition on the Hive Language manual shows this as a configurable property whereas it is not. This may lead to mileading assement of being able to choose a choice of field delimiter.