updated po files.
modified several alerts, and added accelerators for the buttons.
made 2.0.0beta5 release.
modified alert dialogs.
made the order of buttons comply with GNOME HIG.
fixed 'make distcheck'.
made 2.0.0beta4 release.
implemented folder move.
when sending messages, check for line length limit and display warning if exceeds.
check for filename encoding on the first run.
put a warning if invalid filenames appear on the scan of MH folder.
made 2.0.0beta3 release.
added 'Compose new message' and 'Open with Web browser' to the context menu of the text view.
disabled strict checking of caches by stat() and improved the performance.
modified the alert message on deleting folders.
moved the option of max news articles to account prefs.
added an option to encrypt when replying to encrypted message.
updated lt.po and it.po.
added 'Add to address book' to the context menu of textview.
added an option to execute command when new messages arrived.
made 2.0.0beta2 release.
added 'Tools/Filter junk mails in folder' menu.
integrated junk filter setting into common prefs.
unified some frames and checkboxes in common prefs.