Backporting to non-ARC

OK. Backporting to non-ARC is complete. I had a very strange issues when using my macros: applying `JX_AUTORELEASE()` to the `[SubRipItem new]` calls would result in `cur` to reference an NSMutableArray instead of the SubRipItem for some reason. This is why I went with `JX_RELEASE(cur)`. 

I checked for leaks using Instruments and the static analyzer. There appear to be none in non-ARC mode.