* BugFix: Burn button still with sensitive=false when reload packages list.
 - Steps to reproduce:
 Open aptoncd create mode;
 Uncheck all packages (burn buton will be greyed out);
 Reload the list (F5) and all packages will be checked again;
 Burn button still with sensitive=false

* Continue with Download packages features:
 - In the list show only packages installed which are not in cache;
 - Add a context menu to check/uncheck all packages;

* Remove temporary files when Cancel the creation;

* After finishing the process of create/restore show a dialog saying that it's finished;

* Get all the dialogs transient and centralized for the [parent] main_window;

* Get rid with any bug (reported or not);

### for 0.2.x - ~ ###
* add support for download (dropped for 0.2);

## Changelog ##
* Implemented --packages-list=FILE to imput the packages that will be listed in create mode;
* Added a paramether --non-interactive to work together with --packages-list=FILE;
* Added the menu View > Columns, where user can show/hide the Size and Version column in packages list;
* If no package were selected set the sensitive of the "Burn..." button to false until a package be selected;
* Use the menu radio instead the tabs;
* Show the new main 'tab' when aptoncd opens;
* Define if a package is older comparing with the other with the same name in the list, not with the installed one;
 - perhaps splitting into two types of old: 'old_cache' and 'old_installed';
* Show the current mode on Window title, like "APTonCD - Create" or "APTonCD - Restore"
  and update when the modes are toggled;
* Bugfix: Canceling the create process (cancel button) does not actually cancel the
  progress, but freeses the interface;
