Kill meterpreter support.

* Meterpreter seems to fall over on the cmd escaping, and dies if you
try to pass it an array of args (python/java meterpreter on various versions
of osx).

modules/post/osx/manage/mount_share.rb

@@ -32,7 +32,7 @@ class Metasploit3 < Msf::Post
             'joev'
           ],
         'Platform'      => [ 'osx' ],
-        'SessionTypes'  => [ 'shell', 'meterpreter' ],
+        'SessionTypes'  => [ 'shell' ],
         'Actions'       => [
           [ 'LIST',    { 'Description' => 'Show a list of stored network share credentials' } ],
           [ 'MOUNT',   { 'Description' => 'Mount a network shared volume using stored credentials' } ],