pgsql: Improve handling of password reuse in src/bin/scripts programs.

Improve handling of password reuse in src/bin/scripts programs.

This reverts most of commit 83dec5a71 in favor of having connectDatabase()
store the possibly-reusable password in a static variable, similar to the
coding we've had for a long time in pg_dump's version of that function.
To avoid possible problems with unwanted password reuse, make callers
specify whether it's reasonable to attempt to re-use the password.
This is a wash for cases where re-use isn't needed, but it is far simpler
for callers that do want that. Functionally there should be no difference.

Even though we're past RC1, it seems like a good idea to back-patch this
into 9.5, like the prior commit. Otherwise, if there are any third-party
users of connectDatabase(), they'll have to deal with an API change in
9.5 and then another one in 9.6.

Michael Paquier

Branch
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REL9_5_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/3945b6193240cd7fcb5ad3c67e9dca7f12d68b7e

Modified Files
--------------
src/bin/scripts/clusterdb.c | 4 +--
src/bin/scripts/common.c | 48 +++++++++++++++---------------
src/bin/scripts/common.h | 4 +--
src/bin/scripts/createlang.c | 8 ++---
src/bin/scripts/createuser.c | 4 +--
src/bin/scripts/droplang.c | 8 ++---
src/bin/scripts/dropuser.c | 4 +--
src/bin/scripts/reindexdb.c | 8 ++---
src/bin/scripts/vacuumdb.c | 66 +++++++-----------------------------------
9 files changed, 56 insertions(+), 98 deletions(-)