Add "undo" button to thunderbird main bar, and windows accent color as background instead black.

[Daka77]

For people who use Cyrillic(or similar) keyboard цтрл-з(ctrl-z) does nothing, and changing lingo just to undo something is plain annoying, can you just add "undo" button to the bar(the one from which we click "get mail", go to address book etc...
Also please windows accent color for "automatic/default theme" we already have dark and white for those who prefer black background on top.
Both of these comments go for both TB and FF.
Keep up the good work.

Regards,
Vlad.