use numeric error code for detecting unique violations on sl_nodelock

The text of the error message has changed slightly in different postgresql
versions, ie 8.3+.  Using the numeric error code will protect us from this.
This fixes bug 276.

Conflicts:

	src/slon/local_listen.c
Bug #278 - fix various spelling errors found by Debian lintian

Conflicts:
	RELEASE
Add in code to recognize PostgreSQL 9.2 and accept it as a
supported version, rather than warning that we're not sure
updating version number in MSVC config
Add back in find_my_exec() support on platforms that include pgport.
find_my_exec, a postgresql pgport function is again used to find the
location of the slonik binary to locate the share directory.
This is for installs where the install location is not known at
compile time.

Some distributions don't include pgport, this is disabled by default
if you compile with pgport support set to yes (a configure option/check)
then this will be enabled.

Patch submitted by Sandeep Thakkar <sandeep.thakkar@enterprisedb.com>
additional cleanups for pgport find_my_exec support

Clean up configure messaging and avoid a compiler warning by
checking for HAVE_PGPORT after config.h is included
updating documentation to list more recent Postgres versions
Bug 285 fix move set race condition.

During a move set it is possible on subscriber node, that isn't the
old or new origin, for remoteWorkerThread_$oldorigin to start
processing a SYNC event before the ACCEPT_SET is processed
by the remoteWorkerThread_$neworigin.  If the ACCEPT_SET
transaction then commits before the update sl_setsync
query is executed by the remoteWorkertThread_$oldorigin
the update will update a row for the new origin when
it intends to update the old origin.  This messes up
sl_setsync.

This change will add a condition to the WHERE clause so
a remoteWorkerThread won't UPDATE rows for a different
origin
Updating version to 2.1.3
updates to docs and win32 makefile for MS-Windows.
Merge branch 'REL_2_1_STABLE' into REL_2_1_STABLE_multiversion

Conflicts:
	config_msvc.h
	configure.ac
	doc/adminguide/installation.sgml