JS: prevent a null pointer exception from the save-as menu

When a config file has not yet been loaded, don't bother trying to set a default
directory for the save dialog.

Signed-off-by: Harvey Harrison <harvey.harrison@ausenco.com>
JS: Correct the spelling of extension in ColladaModel and ImageModel

Signed-off-by: Harry King <harry.king@ausenco.com>
Signed-off-by: Harvey Harrison <harvey.harrison@ausenco.com>
JS: Remove repeated code in InputAgent.processEntity_Keyword_Value

Signed-off-by: Harry King <harry.king@ausenco.com>
Signed-off-by: Harvey Harrison <harvey.harrison@ausenco.com>
JS: Allow an EntityInput to be cleared in the Input Editor

Signed-off-by: Harry King <harry.king@ausenco.com>
Signed-off-by: Harvey Harrison <harvey.harrison@ausenco.com>
JS: Divide the menu bar initialization for GUIFrame by menu item

Signed-off-by: Harry King <harry.king@ausenco.com>
Signed-off-by: Harvey Harrison <harvey.harrison@ausenco.com>
JS: Add javadocs and headings to GUIFrame methods

Signed-off-by: Harry King <harry.king@ausenco.com>
Signed-off-by: Harvey Harrison <harvey.harrison@ausenco.com>