Check file type on upload

[brizental]

Right we have no validation of filetype whatsoever. If the user tries to input a non-image file, the interface crashes.

[felquis]

For this one, you need to add the accept attribute to the <input type="file" here

idcrop/lib/js/idcrop/IdCrop.js

Lines 152 to 156 in c8e93fb

	var input = document.createElement("input");
	input.type = "file";
	c.toolbarArea.appendChild(input);
	helpers.fakeInput(input, fakeInput);
	helpers.dragDropInput(input, c.displayArea, filenameArea, this);

Check this doc https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/file the Limiting accepted file types section.