pgsql: Teach psql to display comments on languages and casts.

Teach psql to display comments on languages and casts.

The output of \dL (list languages) is fairly narrow, so we just always
display the comment. \dC (list casts) can get fairly wide, so we only
display comments if the new \dC+ option is specified.

Josh Kupershmidt

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/3b17efdfdd846c9bfad1637686e6f18198ea3df5

Modified Files
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doc/src/sgml/ref/psql-ref.sgml | 2 +-
src/bin/psql/command.c | 2 +-
src/bin/psql/describe.c | 55 ++++++++++++++++++++++++++++-----------
src/bin/psql/describe.h | 2 +-
src/bin/psql/help.c | 2 +-
5 files changed, 43 insertions(+), 20 deletions(-)