IMPALA-454 Tab completion in the shell should not depend on case.
IMPALA-454 Tab completion in the shell should not depend on case.

This change adds support for upper case and mixed case tab completion for commands in
the shell.

Change-Id: I5b7083ec71463c9fd60b0a8b788423e2fe8d0ce5
Reviewed-on: http://gerrit.ent.cloudera.com:8080/563
Reviewed-by: Ishaan Joshi <d1d1e60202ec9f2503deb1b724986485a125d802@cloudera.com>
Tested-by: Ishaan Joshi <d1d1e60202ec9f2503deb1b724986485a125d802@cloudera.com>

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