Add default makefile target. Document building

with PGXS.  Convert README to be a .rst file, and
make it and INSTALL valid ReST markup in advance
of merging the two.

README.rst

@@ -0,0 +1,160 @@
+=====================================================
+repmgr: Replication Manager for PostgreSQL's clusters
+=====================================================
+
+Introduction
+============
+
+PostgreSQL 9.0 allow us to have replicated hot standby servers 
+which we can query and/or use for high availability.
+
+While the main components of the feature are included with
+PostgreSQL, the user is expected to manage the high availability
+part of it.
+
+repmgr allows you to monitor and manage your replicated PostgreSQL
+databases as a single cluster.
+
+repmgr works in two components:
+
+* repmgr: command program that performs tasks and then exits
+* repmgrd: management and monitoring daemon that watches cluster
+
+
+COMMANDS
+========
+
+None of this commands need the repmgr.conf file but they need to be able to
+connect to the remote and local database.
+
+You can teach it which is the remote database by using the -h parameter or 
+as a last parameter in standby clone and standby follow. If you need to specify
+a port different then the default 5432 you can specify a -p parameter.
+Standby is always considered as localhost and a second -p parameter will indicate
+its port if is different from the default one.
+
+* master register
+
+  * Registers a master in a cluster, it needs to be executed before any node is 
+    registered
+
+* standby register
+
+  * Registers a standby in a cluster, it needs to be executed before any repmgrd 
+    is executed
+
+* standby clone [node to be cloned] 
+
+  * Backup via rsync the data directory of the primary. And creates the recovery file
+    we need to start a new hot standby server.
+    It doesn't need the repmgr.conf so it can be executed anywhere in the new node.
+    So, you can step where you want your new data directory and execute::
+
+      ./repmgr standby clone 10.68.1.161
+
+    or from wherever you are::
+
+     ./repmgr -D /path/to/new/data/directory standby clone 10.68.1.161
+
+    That will make a backup of the primary then you only need to execute::
+
+      pg_ctl -D /your_data_directory_path start
+
+
+* standby promote 
+
+  * Allows manual promotion of a specific standby into a new primary in the event of a failover
+    This needs to be executed on the same directory where the repmgr.conf is in the standby or 
+    then use the -f option to indicate where the repmgr.conf is.
+    Doesn't need any additional arguments::
+
+      ./repmgr standby promote
+
+    That will restart your standby postgresql service
+
+* standby follow 
+
+    * Allows the standby to re-point itself to a new primary indicated as a parameter.
+      This needs to be executed on the same directory where the repmgr.conf is in the standby or 
+      then use the -f option to indicate where the repmgr.conf is.  Example::
+
+        ./repmgr standby follow
+
+PREREQUISITES
+=============
+
+Primary must be configured with the following in its ``postgresql.conf``::
+
+  listen_addresses='*'
+  wal_level = 'hot_standby'
+  archive_mode = on
+  archive_command = 'cd .'
+  max_wal_senders = 10
+  wal_keep_segments = 5000      # 80 GB required on pg_xlog
+  hot_standby = on
+
+Also you need to add the machines that will participate in the cluster in
+``pg_hba.conf``, such as::
+
+  host     all              all         10.8.0.0/24         trust
+  host     replication      all         10.8.0.0/24         trust
+
+
+EXAMPLES
+========
+
+Suppose we have 3 nodes: node1 (the master), node2 and node3
+
+To make node2 and node3 be standbys of node1, execute this on both nodes
+(node2 and node3)::
+
+  repmgr -D /var/lib/postgresql/9.0 standby clone node1
+
+If we lose node1 we can run on node2::
+
+  repmgr -f /home/postgres/repmgr.conf standby promote 
+
+Which makes node2 the new master.  We then run on node3::
+
+  repmgr standby follow
+
+To make node3 follow node2 (rather than node1)
+
+If now we want to add a new node we can a prepare a new server (node4) and run::
+
+  repmgr -D /var/lib/postgresql/9.0 standby clone node2
+
+NOTE: you need to have PGDIR/bin in your path, if you don't want that as a 
+permanent setting you can do it this way::
+
+  PATH=$PGDIR/bin:$PATH repmgr standby promote
+
+CONFIGURATION FILE
+==================
+
+``repmgr.conf`` is looked for in the directory repmgrd or repmgr exists.
+The configuration file should have 3 lines:
+
+* cluster : the name of this cluster
+* node    : specify the number of this node inside the cluster
+* conninfo: specify how we can connect to this node's PostgreSQL service
+
+REPMGR DAEMON
+=============
+
+It reads the repmgr.conf file in current directory or as indicated with -f 
+parameter looks if the standby is in repl_nodes and if it is not add it.
+
+Before you can run the repmgr daemon (repmgrd) you need to register a master
+and at least a standby in a cluster, for that you need to use the MASTER 
+REGISTER and STANDBY REGISTER commands.
+
+For example, following last example and assuming that repmgr.conf is in postgres
+home directory you will run this on the master::
+
+  repmgr -f /home/postgres/repmgr.conf master register
+
+and the same in the standby.
+
+The repmgr daemon creates 2 connections: one to master and other to standby.
+