Fix issue 717 -- data_editor

[teddphil]

Fixes #717.

The issue was caused by the settings of UI component display. The settings of displaying echo file component and output file component are managed at lines 131 to 136 in pspm_data_editor. The lines functioned as following:

• If users call the GUI directly without specifying options in command, it will always display echo file and output file.
• If users call the GUI with specifying options, it will only display output_file when users have not specified output_file, and will only display epoch_file if users have specified epoch_file.

I am not fully clear why the logic was set to be like this. I think maybe we can discuss about how we want to set this. Currently I have disabled these customisations, so the two epoch_file and output_file modules will always be displayed no matter how users specify options subfields.