bug 299 - put the WAKEUP event at the front of the event queue instead of the back.

This will prevent the remoteWorker thread for an old-origin from pulling
the set that was just moved if a SYNC event is already queued
don't process a set if sl_setsync has the initial :1:1: snapshot id
this snapshot id is reserved for setting up the value indicates that
an even (ie the ACCEPT_SET) is still pending.

Also be explicit about the origin this remote worker is querying
sl_setsync for.
documentation changes to reflect incompatibilities between slony 2.1.x and 2.2.0
updating minor upgrade instructions to reflect that slony server files are now versioned
and both versions can co-exist in the $libdir and $sharedir at the same time
documentation sgml fixes
memory leak fixes in sync_helper

dstring_terminate does not call free() to deallocate memory dstring_free() does
array_length() doesn't exist on PG 8.3 use array_upper() instead
documentation changes to reflect incompatibilities between slony 2.1.x and 2.2.0
updating minor upgrade instructions to reflect that slony server files are now versioned
and both versions can co-exist in the $libdir and $sharedir at the same time
documentation sgml fixes
Tweak to release notes
Shift some anachronisms to the Obsolete section
add documentation that mentions that the filenames of installable files have changed
More fixes to anachonisms
More textual changes
Fix typo
Lots of fixes to anachronisms in FAQ
additional dstring_free() to fix an additional memory leak in sync_helper
add in a check/test to ensure that the backup node in a failover is a forwarding subscriber

If the backup node is not a forwarding subscriber to all of the sets from the origin
then the failover can't complete.  It is best to check this early on and warn the user
before the failover actually starts.
The table definitions we create on a 2.1 -> 2.2 upgrade should match the updated DDL in slony1_base.sql
This is to fix bug 306