removed direct inclusion of <glibconfig.h> and <glib/gwin32.h> (fixes Bug #53).
OS X: changed the location of settings to ~/Library/Application Support/Sylpheed .
use 'open' command on OS X.
merged plug-in update check and automatic update patch.
added 'Junk' special folder and automatically create it when not exist.
also load plug-ins from user plug-in directory.
made default browser command xdg-open.
merged plugin-test branch into trunk.
implemented the modification of search folder condition.
win32: implemented remote command using TCP socket.
changed the license of LibSylph from GPL to LGPL.
made some core modules library (libsylph).