Merge bugfix #2546 from poco-1.9.1 (#2548)

* Merge bugfix #2546 from poco-1.9.1

* Fixed ODBC SessionImpl

* Fixed missing methods in PostresSQL and testsuit

* Fixed missing method in SQLite SessionImpl

* Use mysql_refresh() instead of mysql_reset_connection()

* Use mysql_reset_connection() if it is available

Use mysql_reset_connection() only if MySQL version is >= 5.7 or MariaDB
version is >= 3.0.0 otherwise fall back to myslq_refresh()

SQL/MySQL/src/SessionImpl.cpp

@@ -267,6 +267,13 @@ void SessionImpl::close()
 }
 
 
+void SessionImpl::reset()
+{
+	if (_connected)
+		_handle.reset();
+}
+
+
 void SessionImpl::setConnectionTimeout(std::size_t timeout)
 {
 	_handle.options(MYSQL_OPT_READ_TIMEOUT, static_cast<unsigned int>(timeout));