Failing test for huge RACBacktrace list
Autorelease previous backtrace frames
Revert "Autorelease the backtrace instead of precise lifetiming it"

Now handled by 21d76e2.

This reverts commit 40a88f7dede48feadbf62f60a45434e123ce4bde.
Merge pull request #1169 from ReactiveCocoa/backtrace-stack-overflow

Fix stack overflow when freeing long backtrace chains