pgsql: Doc: marginal hacking to remove some PDF build warnings.

Doc: marginal hacking to remove some PDF build warnings.

This patch eliminates a few more "exceed the available area" warnings
whose causes aren't particularly connected to anything else.

The only one really worthy of comment is that I increased the space
allowed for an <orderedlist>'s numbers, because the default of 1em
doesn't quite work for more than one digit.  The rest are one-off
insertions of &zwsp; and suchlike tweaks, in places where they
shouldn't do any damage to the material.  (In particular, although
I split some long identifiers with zwsp's, there are other nearby
occurrences of each one; so those changes shouldn't hurt greppability
of the document sources.)

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/336aa51b70e9cf7da3969a3f102ff4913717083d

Modified Files
--------------
doc/src/sgml/bgworker.sgml           | 2 +-
doc/src/sgml/dblink.sgml             | 1 -
doc/src/sgml/information_schema.sgml | 4 ++--
doc/src/sgml/lobj.sgml               | 4 ++--
doc/src/sgml/stylesheet-fo.xsl       | 1 +
doc/src/sgml/textsearch.sgml         | 4 ++--
6 files changed, 8 insertions(+), 8 deletions(-)