Fix error message in impala-shell for queries that crash the impalad

An anti-join query in IMPALA-1175 revealed that the shell
mishandled the exception when the impalad would crash. This
fix prints the correct error message and sets the shell
state as disconnected.

Note there isn't a way to test this easily due to the difficulty
in coming up with a query that will crash the impalad.

Change-Id: I534674880db224a0d93dfd8bd2c081a12b65532b
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3998
Reviewed-by: Abdullah Yousufi <abdullah.yousufi@cloudera.com>
Tested-by: jenkins
Analytic functions BE implementation

Evaluates analytic functions with a single pass over sorted input rows and using
a BufferedTupleStream to buffer output rows. It is assumed that the input has
already been sorted on all of the partition keys and then the order by exprs.
Analytic functions are implemented as aggregate functions.

Current implementation only supports partition clauses and order by clauses with
the default window (i.e. UNBOUNDED PRECEDING to CURRENT ROW).

Change-Id: I93f37a4e7fd8167261bf86c2a5b7c8569a1f7b11
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3939
Reviewed-by: Matthew Jacobs <mj@cloudera.com>
Tested-by: jenkins