Add ng2-img-tools to Image Manipulation

[bergben]

ng2-img-tools is a collection that allows to

• resize images according to the proportions
• resize images to a certain maximal size (width and / or height)
• resize images exactly to a certain size (by cropping if necessary). Useful to create thumbnails.
• compress images to a certain filesize
• crop images
• get an oriented image according to its EXIF data

ng2-img-tools depends on ng2-img-max: https://github.com/bergben/ng2-img-max

• Don't create a pull request to add a library, instead use devarchy.com/angular-components.
• Only create a pull request to change the categorization.
• Open an issue if you are not sure how to change the categorization to fit a library you want to add.