4.0.0:

* Updated to GTK 3

* Updated to Python 3

* Added a search bar for pigeons

* Added a racepoints map

* Added indication of available pedigree space in extra boxes

* Added application update dialog

* Added icon to indicate hidden pigeons

* Added option to change number of generations in pedigree tab

* Added placeholders in band entry

* Added window to show and filter all breeding record

* Added a theme selector on Windows

* Added loft as optional extra line on printed pedigree

* Move band format options to a popover

* Improved error reporting on invalid band entry

* Show zoom icon when hovering over pigeon image

* Show add and remove buttons on image when editing a pigeon

* Changed date entry dialog to a popover

* Show list of pigeons in medication dialog

* Show some extra columns by default in main treeview

* Show message in the statusbar when running a development version

* Handle corrupt configuration file

* Fixed adding pigeons wit hthe default band format through the breeding option

* Fixed error in rare cases when reporting an error

* Fixed sending report when results import fails

* Improved results import dialog

* Show message about media files in backup dialog

* Removed update check when reporting an error

* Removed distance calculator

* Removed racepoint manager

* Improved look for multiple widgets

* Updated translations

* Many various UI changes

* Many various code changes