updated po files.
added 'Set as (not) junk mail' to the summary context menu.
po/tr.po: fixed a typo which caused crash.
added 'Mark all read' to the folder context menu.
made 2.2.6 release.
added the option for MIME filename encoding method.
made 2.2.2 release.
made 2.2.1 release.
made 2.2.0 release.
updated makewin32.sh, and hu.po. Made 2.2.0beta8 release.
added the help of command line options.
added Arabic encoding, and 2.2.0beta7 release.
made 2.2.0beta6 release.
'File/Insert signature' now inserts signature into current cursor position.
implemented clearing of IMAP4 message caches on exit.
added tooltip for search entry.
a bit of optimization for toggling threads.
added filter conditions of status such as 'unread', 'mark', 'color-label', and 'mime'.
perform show/hide on trayicon click. Implemented popup menu on trayicon.
replaced 'Search messages...' with 'Edit search condition...' on virtual folder.
modified the message of deleting search folder.
made 2.2.0beta2 release.
made 2.2.0beta1 release.
made 2.1.9 release.
added an option to update only INBOX on checking new messages of IMAP4 accounts.
enabled custom queue folder.
added Vietnamese translation.