Fix the description of "layer" param in Action::LayerSetDesc

"Layer to be moved" still is the description of Action::LayerMove
Enhancement #335 - UI : Renaming a value node, display old name

Add value_provided to ParamDesc
Enhancement #335 - UI : Renaming a value node, display old name

Add virtual bool Action::Base::get_param { return false; }
Add virtual bool Action::CanvasSpecific::get_param { return false; }
Enhancement #335 - UI : Renaming a value node, display old name

Add set_value_provided() for name parameter
Add Action::ValueNodeRename::get_param
Enhancement #335 - UI : Renaming a value node, display old name

In Instance::process_action , is the param is user_supplied,
check if it's also value_provided, and get it.
Enhancement #335 - UI : Renaming a value node, display old name

Give same behavior to Action::LayerSetDesc (current name displayed in dialog)

- set_value_provided() for new_description param
- implement Action::LayerSetDesc::get_param
Merge pull request #102 from d-j-a-y/djay_action_param_get_value

Display old name when renaming an exported value (closes #335)
Fix some typo of action defination
Cleanup
Format code
Rename menu "Reset to default Setup values" to "Restore Default Preferences Values"
Reorder frame related menu commands in View menu
Move "Preview Window"  of View to Window
Fix missing actions issue by pre-define actions
Cleanup unused tool menu items, since tool menu already removed from menubar
Callback Keyframe Actions
Replace GTK+ stock icons with synfig version frame related icon in View menu.
Rename "Restore Default Preferences Values" menu item to "Restore Default Settings"
Implement a "Restore Default Settings" button on "Preference" dialog

Implement Restore Default Settings button
Remove the Restore Default Settings submenu from Edit
Replace Close with Cancel GtkStock for Preference dialog
Remove Apply button of Preference dialog
Re-order these three buttons as
[Restore Default Settings] [Cancel] [Ok]
Add a seprator between synfig panels and opened documents in Window menu