Enterprise style header beautification:
- reduce the amount of wasted vertical space by limiting the height of the div
with the icon. this doesn't happen in older KMails, so maybe this is a webkit thing.
- make the "From", "To", "Cc", "Bcc" font sizes all 10px instead of 6px
(Bertjan was right: 6px is just too darn small)

MERGE: 4.7