Move some parts of the UI construction to glade files.

I have move some parts that were declared programatically
to the glade files.
Add Open Project and Preferences buttons to opened files headebar.
Modify panel creation and moving implementation.

Every pannel has a property ToolBarMode that indicates which
page of the headerbar notebook should we enable. In addition
we have added a new set_panel method in the window class that
makes the process easier.
Add behaviour to search button.
Remove file title from headebar.
Add signal to Edit Panel.