pgsql: doc: Fix DocBook XML validity

doc: Fix DocBook XML validity

The main problem is that DocBook SGML allows indexterm elements just
about everywhere, but DocBook XML is stricter. For example, this common
pattern

<varlistentry>
<indexterm>...</indexterm>
<term>...</term>
...
</varlistentry>

needs to be changed to something like

<varlistentry>
<term>...<indexterm>...</indexterm></term>
...
</varlistentry>

See also bb4eefe7bf518e42c73797ea37b033a5d8a8e70a.

There is currently nothing in the build system that enforces that things
stay valid, because that requires additional tools and will receive
separate consideration.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/3a9d430af515e9dd8a9d34a4011367e667a66521

Modified Files
--------------
doc/src/sgml/auth-delay.sgml | 6 +-
doc/src/sgml/auto-explain.sgml | 48 +--
doc/src/sgml/config.sgml | 733 ++++++++++++++++++++++------------
doc/src/sgml/dfunc.sgml | 56 ++-
doc/src/sgml/installation.sgml | 7 +-
doc/src/sgml/libpq.sgml | 4 +-
doc/src/sgml/logicaldecoding.sgml | 2 +-
doc/src/sgml/pageinspect.sgml | 42 +-
doc/src/sgml/pgfreespacemap.sgml | 6 +-
doc/src/sgml/pgstatstatements.sgml | 16 +-
doc/src/sgml/pgstattuple.sgml | 7 +-
doc/src/sgml/plperl.sgml | 278 +++++++------
doc/src/sgml/pltcl.sgml | 23 +-
doc/src/sgml/protocol.sgml | 3 +-
doc/src/sgml/queries.sgml | 16 +-
doc/src/sgml/recovery-config.sgml | 55 +--
doc/src/sgml/ref/alter_table.sgml | 13 +-
doc/src/sgml/ref/pg_recvlogical.sgml | 8 +-
doc/src/sgml/ref/psql-ref.sgml | 24 +-
doc/src/sgml/rules.sgml | 4 +-
doc/src/sgml/runtime.sgml | 30 +-
doc/src/sgml/sepgsql.sgml | 20 +-
doc/src/sgml/sslinfo.sgml | 54 +--
doc/src/sgml/textsearch.sgml | 26 +-
24 files changed, 903 insertions(+), 578 deletions(-)