Completely new Icelandic translation.
OS X: fix Cmd+W in auxiliary windows.

Pressing Cmd+W should close the active window, not the main one.
Fix cs translation for "About Poedit" to be consistent with OS X.
Fix Cmd+Q on OS X with unsaved documents.

Properly quit the app after confirmation; previously, the intention to
quit would be forgotten and the app would still be running without
windows open.
Set focus in language dialog.
Autocomplete LanguageCtrl.
Update wxWidgets version.
Fix weirdly misbehaving Check for Updates on OS X.

The menu item would appear, disappear or be duplicated following some
weird logic due to the incredibly hacky way of implementing it.  Do it
in a cleaner way (requires wx post 3.0).
Move Catalog Manager into app menu on OS X.

That (or the Window menu) is more appropriate than the File menu.
Make sure the bottom split panel is tall enough to fit plural forms UI.
Fix broken handling of zh_CN in LanguageCtrl.

It would be formatted into a string that wouldn't then be accepted as valid input.
Reorder file warnings by severity.

The last message set is the one shown, so make sure it's the most
important one of them.
Check that Project-Id-Version is set.

Require it in the properties dialog.  Warn about missing header when
loading a file.  Clear the default invalid value ("PROJECT VERSION")
when loading PO files.
OS X: Implement fullscreen button.
Move bitmaps into artwork/ directory.