Various little fixes

Ok, it's my first pull request (and play with Git), so sorry if I f*'d something up. :)

- `image["href"]` style indexing replaced to image.href
- overcomplicated emptiness checks were simplified to `if(image.title) …`
- `if(image.title)` and `if(image.alt)` checks added to `buildImage()`
- spaces/tabs removed from line endings
- repetitive jQuery wrappings removed, instead `var $thing = $(thing);` lines added
- Verbose `images[index]["alt"] = …` lines simplified to `image.alt`
- `processesImages` renamed to `processImages`
- passing jQuery object as a first argument removed from `checkWidth($, …)` and `processesImages($, …)`
- `settings.onArrange` callback almost added, but I dunno what to do with `checkWidth`'s continuous checks