pginstaller - pginst: Check that the selected port is not in use before

Log Message:
-----------
Check that the selected port is not in use before allowing installation to proceed.

Modified Files:
--------------
pginst/ca:
pginstca.c (r1.30 -> r1.31)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pginstaller/pginst/ca/pginstca.c.diff?r1=1.30&r2=1.31)
pginst/util:
builddir.pl (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pginstaller/pginst/util/builddir.pl.diff?r1=1.1&r2=1.2)
pginst/wxi:
Makefile (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pginstaller/pginst/wxi/Makefile.diff?r1=1.1&r2=1.2)