Fixed array handling in ecpg.

When ecpg was rewritten to the new protocol version not all variable types
were corrected. This patch rewrites the code for these types to fix that. It
also fixes the documentation to correctly tell the status of array handling.

doc/src/sgml/ecpg.sgml

@@ -1377,10 +1377,13 @@ EXEC SQL END DECLARE SECTION;
     <title>Arrays</title>
 
     <para>
-     SQL-level arrays are not directly supported in ECPG.  It is not
-     possible to simply map an SQL array into a C array host variable.
-     This will result in undefined behavior.  Some workarounds exist,
-     however.
+     Multi-dimensional SQL-level arrays are not directly supported in ECPG.
+     One-dimensional SQL-level arrays can be mapped into C array host
+     variables and vice-versa.  However, when creating a statement ecpg does
+     not know the types of the columns, so that it cannot check if a C array
+     is input into a corresponding SQL-level array.  When processing the
+     output of a SQL statement, ecpg has the necessary information and thus
+     checks if both are arrays.
     </para>
 
     <para>