add an option to choose the suffix for 2x images
Ensure the we are only modifying the path name when adding @2x.

If `document.createElement()` exists use that to create an 'a' element to
parse the URL otherwise simply assume the first '?' seperates the query
params from the rest of the URL (weak assumption).

Reguardless of method used, run regex replace on the path part only to
prevent @2x from being added to query params.

See added unit test for more info.
Simplify REGEX

No need to look for '?'.
Allow some images to not be processed by Retina

We had a very difficult to track down bug wherein Retina was setting the width and height of an image to 0px after an ng-show trigger. This should not be happening, and one easy fix is to allow individual images to not be processed by Retina.
possible to exclude image with 'data-no-retina'
exclude images with data-no-retina

Images were'nt loaded in 'retinaImages'
Added data-no-retina
Move to Grunt for build.
Grunt compress
Tweaking module versions for node ~0.8.x
Drop support for Node 0.8
Remove Makefile.
Merge branch 'master' of https://github.com/tobaiasjl/retinajs into tobaiasjl-master
Minor change to improve backwards compatibility with only slightly older browsers.
Remove redundant check for data-no-retina.
Correct boolean.
Merge branch 'feature/grunt-build' into release-1.3.0
Corrected merge conflict.
Address issue #130
Merge in pull request #115.