pgsql: Cleanups from the remove-native-krb5 patch

Cleanups from the remove-native-krb5 patch

krb_srvname is actually not available anymore as a parameter server-side, since
with gssapi we accept all principals in our keytab. It's still used in libpq for
client side specification.

In passing remove declaration of krb_server_hostname, where all the functionality
was already removed.

Noted by Stephen Frost, though a different solution than his suggestion

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/0294023a6b1c5df7683707a77238ab634d4ea8c1

Modified Files
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doc/src/sgml/client-auth.sgml | 15 ++++++++-------
doc/src/sgml/config.sgml | 14 --------------
src/backend/libpq/auth.c | 1 -
src/backend/utils/misc/guc.c | 13 -------------
src/backend/utils/misc/postgresql.conf.sample | 3 +--
src/include/libpq/auth.h | 2 --
src/include/libpq/hba.h | 1 -
7 files changed, 9 insertions(+), 40 deletions(-)