* Change image render hook behavior. By default it will
not process images with width lower than 1280 pixels
* Make resize options global and allow them to be
changed via config
* Change the default resize dimensions from 1200x, 800x
and 500x to 1280x, 960x and 640x
* Update image placeholder generation method (used to
reduce reflow). It should use less space now
* Update README with information about image processing
* Improve page/post detection
* Update images for Lorem Ipsum post and contact page
on exampleSite
* Other minor changes
