Fixed typo

Ignore-this: 1642bc8664947f2b3eecd07e80767585

darcs-hash:20131105161107-b22ec-6425d3b6d0ceb96f2f5d7224eef6fd21ef6f8b53
Added audio.muted runtime setting to SIPSimpleSettings

Ignore-this: 8faf0fdd7792775c8dc17d45fb9f8863

darcs-hash:20131115104252-b22ec-086a28a7b72e2e8dfc4d362de1338111621f405d
Post SIPApplicationWillEnd even if Engine failed

Ignore-this: 3e2de58ae64d21b00f59973f244aa387

darcs-hash:20131115132459-56b4d-8be94ca16f54b122f5a703e02e59d276ab1701d4