Turn on prepared statements again.

* Changed bin param integer to start with `@0` so each with index always works.
* The `supports_statement_cache?` is still in there for AR's testing reflection now.

Author: metaskills

lib/active_record/connection_adapters/sqlserver_adapter.rb

@@ -48,6 +48,7 @@ def initialize(connection, logger, pool, config)
         # AbstractAdapter Responsibility
         @schema_cache = SQLServer::SchemaCache.new self
         @visitor = Arel::Visitors::SQLServer.new self
+        @prepared_statements = true
         # Our Responsibility
         @config = config
         @connection_options = config

lib/arel/visitors/sqlserver.rb

@@ -13,7 +13,7 @@ class SQLServer < Arel::Visitors::ToSql
       # SQLServer ToSql/Visitor (Overides)
 
       def visit_Arel_Nodes_BindParam o, collector
-        collector.add_bind(o) { |i| "@#{i}" }
+        collector.add_bind(o) { |i| "@#{i-1}" }
       end
 
       def visit_Arel_Nodes_Offset o, collector