start breaking out a ui feature to set an input step (#253)

* start

* refactoring

* working

* version bump

examples/lib/imageSelection.js

@@ -1,50 +0,0 @@
-function setupFileHandling(_sequencer, dropzoneId, fileInputId) {
-
-  dropzoneId = dropzoneId || "dropzone";
-  var dropzone = $('#' + dropzoneId);
-
-  fileInputId = fileInputId || "fileInput";
-  var fileInput = $('#' + fileInputId);
-
-  var reader = new FileReader();
-
-  function handleFile(e) {
-
-    e.preventDefault();
-    e.stopPropagation(); // stops the browser from redirecting.
-
-    if (e.target && e.target.files) var file = e.target.files[0];
-    else var file = e.dataTransfer.files[0];
-    if(!file) return;
-
-    var reader = new FileReader();
-    
-    reader.onload = function onFileReaderLoad() {
-      var loadStep = _sequencer.images.image1.steps[0];
-      loadStep.output.src = reader.result;
-      _sequencer.run(0);
-      loadStep.options.step.imgElement.src = reader.result;
-    }
-
-    reader.readAsDataURL(file);
-  }
-
-  fileInput.on('change', handleFile);
-
-  dropzone[0].addEventListener('drop', handleFile, false);
-
-  dropzone.on('dragover', function onDragover(e) {
-    e.stopPropagation();
-    e.preventDefault();
-    e.dataTransfer.dropEffect = 'copy'; // Explicitly show this is a copy.
-  }, false);
-
-  dropzone.on('dragenter', function onDragEnter(e) {
-    dropzone.addClass('hover');
-  });
-
-  dropzone.on('dragleave', function onDragLeave(e) {
-    dropzone.removeClass('hover');
-  });
-
-}