Move category and group view to GlCategoryList
Add desktop file
Move application to GlApplication
Add "quit" and "about" actions
Add application menu, using GResource
Use GtkBuilder for application window
Set program name and application window title
Use GtkBuilder for children of application window
Add image to individual event view rows
Display the name of the logging executable

Show the name, in bold, of the executable which is logging a message,
above the log message in the event view.
Attach a journal cursor string to each event row
Add handler for activating an event view row

Read the cursor from the activated row and seek to that position in the
journal.
Make GlEventView a GtkStack

Move the list box that was GlEventView to a private struct.
Add skeleton detailed event view
Go back from the detailed to the event view
Add placeholder toolbar buttons
Add a window action for the view mode
Make GlWindow a template widget
Add visible properties to GtkBuilder XML
Make GlCategoryList a template widget