relax SVN archive

The Base_value class can now accept the element_type arg value of 'default'.

This will then use the TextCtrl.

The add_keyarg() wiz_element_type arg default is now 'default' to be able to handle all element types.

The previous default of 'text' for a TextCtrl was causing failures with certain wizard GUI elements.

The relax controller is now shown for the auto-generated GUI user functions if 'display' is set.

This is the 'display' variable in the user function data store. This allows all the user functions
which print to STDOUT to pop up the controller in front of the user, so they see the result.

The user function data structure now accepts the 'display' boolean variable.

This is used to indicate that a user function would like to display some output to STDOUT.

Fixes for the argument checking in the auto-generated user functions.

All of the user function argument arguments are now handled by the add_keyarg() method.

All of the argument checking types are now supported for the auto-generated user functions.

This covers every type of arg_check.is_*() function used in relax.

Boolean argument types are now supported by the auto-generated GUI user functions.

The Selector_bool object and element_bool() wizard page method have been written for this.

The can_be_none user function argument argument is now used.

This is needed for proper argument checking in the auto-generated user functions.

The wizard page GetValue() method now returns None if the corresponding key is missing.

This is needed for the directory arguments as these are not shown in the GUI.