Hooking into VM
---------------

   To hook Mailcrypt into VM, use the following lines:

     (add-hook 'vm-mode-hook 'mc-install-read-mode)
     (add-hook 'vm-summary-mode-hook 'mc-install-read-mode)
     (add-hook 'vm-virtual-mode-hook 'mc-install-read-mode)
     (add-hook 'vm-mail-mode-hook 'mc-install-write-mode)