Skinny: do not add call to missed calls list if answered elsewhere.

Patch updates skinny devices with a SKINNY_CONNECTED callstate if an
inbound ringing or callwaiting call is answered elsewhere.


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@405367 f38db490-d61c-443f-a65b-d21fe96a405b