pgtcl - libpgtcl: * Add "escape_bytea" and "unescape_bytea" to the

Log Message:
-----------
* Add "escape_bytea" and "unescape_bytea" to the methods that can be
invoked from $conn.

* Extend pg_escape_bytea to allow a connection handle to be specified.
If specified, libpq's PQescapeByteaConn is used rather than
deprecated PQescapeBytea, which can return incorrect results since
it can't determine whether standard-conforming strings are enabled.

If the "$conn escape_bytea ..." method is used, the connection-handle
version is automatically used.

* Detect if lo_truncate is available in libpq or not and, if not, return
an error if it is attempted.

Modified Files:
--------------
libpgtcl:
ChangeLog (r1.53 -> r1.54)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgtcl/libpgtcl/ChangeLog.diff?r1=1.53&r2=1.54)
configure (r1.16 -> r1.17)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgtcl/libpgtcl/configure.diff?r1=1.16&r2=1.17)
configure.in (r1.15 -> r1.16)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgtcl/libpgtcl/configure.in.diff?r1=1.15&r2=1.16)
libpgtcl/generic:
pgtclCmds.c (r1.71 -> r1.72)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgtcl/libpgtcl/generic/pgtclCmds.c.diff?r1=1.71&r2=1.72)
pgtclCmds.h (r1.22 -> r1.23)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgtcl/libpgtcl/generic/pgtclCmds.h.diff?r1=1.22&r2=1.23)
pgtclId.c (r1.45 -> r1.46)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgtcl/libpgtcl/generic/pgtclId.c.diff?r1=1.45&r2=1.46)