relax SVN archive

Fix for the Selector_dir class - the default of None needs to be converted to wx.EmptyString early.

This was causing TypeErrors in the wizard pages.

The simple Value wizard page element default for an integer is now a wx.SpinCtrl.

If the element_type arg is set to 'default' and the data type is integer, then a wx.SpinCtrl will be
used.

Whitespace clean up.

The align_tensor.init param_types arg is now a ComboBox with the choices in the GUI.

The generic_fns.grace.get_data_types() function is even more fail proof.

The return_data_desc() call was sometimes raising a RelaxError when not implemented for certain
analyses.

Converted the grace user functions to the auto-generation design.

This required created the generic_fns.grace.get_data_types() function for returning the data type
descriptions and values for the current data pipe. This is to replace the code in the old grace
user function update_parameters() method so that the data type fields are updated according to the
analysis.

The Value.SetValue() method can handle default values when the list is empty.

For the Value wizard page element, the default can be the string or data for a ComboBox now.

If the default is a data value, then this is translated to the string. This allows the default in
the user function data objects to be either the string or data value, removing a source of coding
errors.

Fix for the Selector_file GUI wizard page element - the default value cannot be None.

The value of None was translated to wx.EmptyString too far down in the initialisation, after it was
being used. This caused most file selection GUI elements to fail.

Converted the frq user functions to the auto-generation design.