Upgrade settings as recommended by Xcode 4.6
Tried to add timeoutTimer as an ivar
Revert "Tried to add timeoutTimer as an ivar"

This reverts commit 0dab779c8fd93be0ba8506a8cd6b1725c7091a3b.
Tried checking timeout timer

it appears the exception is being thrown on block copy.  WTF
Addressed timeoutTimer cancellation issues

- assign a cancel handler to the dispatch source and release the timer there
- Also provide more verbose sftp error messages in some cases