pgsql: Update copyright for 2016

Update copyright for 2016

Backpatch certain files through 9.1

Branch
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REL9_3_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/6d90d6a5ce0ca6fcf17b9a6e15ced5315941aa0e

Modified Files
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COPYRIGHT               |    2 +-
doc/src/sgml/legal.sgml |    6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)