pgsql: Change chapter titles thus: III.

Log Message:
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Change chapter titles thus:

III. Server Administration
15. Installation from Source Code
16. Installation from Source Code on Windows
17. Server Setup and Operation

to give users of binary installations a better idea where to start reading.

suggested by Nikolay Samokhvalov

Modified Files:
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pgsql/doc/src/sgml:
install-win32.sgml (r1.50 -> r1.51)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/install-win32.sgml?r1=1.50&r2=1.51)
installation.sgml (r1.317 -> r1.318)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/installation.sgml?r1=1.317&r2=1.318)
runtime.sgml (r1.424 -> r1.425)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/runtime.sgml?r1=1.424&r2=1.425)