Brush tool : Replace Gtk::Table (deprecated gtk container)

* Gtk::Box as main container
* Gtk::Grid for brushes container
Brush tool : Replace ToggleButton by RadioButton

All the brushs can now be selected by RadioButton holded by a unique group. So only one brush can be selected at the same time.
Brush tool : Fix 605 - Brush do nothing without image layer

If not image found, add one.
Brush Tool : #615 - Brush tool do not (always) used selected color

Fix rgb to hsv conversion
Linux build: Fix permission issue for deb packages
Merge https://github.com/synfig/synfig
Add two dialogs for loading audio and image file form parameter widget
Add image list (*.lst) file support

to Import dialog and Import Image Layer Parameter Panel ->  Filename dialog
Reorder Open and Open history buttons
Code formating.
Rename spal file fileter according to other file chooser dialogs
Select proper dialog according to selected layer.
Add filechooser for render dialog.
Use gtk message dialog