added pypyodbc.py, thanks Derek

VERSION

@@ -1 +1 @@
-Version 2.4.1-alpha.2+timestamp.2013.02.04.16.44.47
+Version 2.4.1-alpha.2+timestamp.2013.02.05.08.45.51

gluon/dal.py

@@ -339,7 +339,10 @@ if not 'google' in DRIVERS:
         LOGGER.debug('no Oracle driver cx_Oracle')
 
     try:
+        #try:
         import pyodbc
+        #except ImportError:
+        #    from contrib.pypyodbc import pypyodbc as pyodbc
         DRIVERS.append('MSSQL(pyodbc)')
         DRIVERS.append('DB2(pyodbc)')
         DRIVERS.append('Teradata(pyodbc)')