Add semantic filenames before uploading to S3.

audiogram/index.js

 Audiogram.prototype.render = function(cb) {
 
   var self = this,
-      q = queue(1);
+      q = queue(1),
+      identifier = self.settings.identifier;
+ ;
 
   this.status("audio-download");
 
   q.defer(this.combineFrames.bind(this));
 
   // Upload video to S3 or move to local storage
-  q.defer(transports.uploadVideo, this.videoPath, "video/" + this.id + ".mp4");
+  q.defer(transports.uploadVideo, this.videoPath, "video/" + identifier + ".mp4");
 
   // Delete working directory
   q.defer(rimraf, this.dir);
   q.await(function(err){
 
     if (!err) {
-      self.set("url", transports.getURL(self.id));
+      self.set("url", transports.getURL(identifier));
     }
 
     logger.debug(self.profiler.print());

client/index.js

       citation = preview.citation(),
       label = preview.label(),
       selection = preview.selection(),
-      file = preview.file();
+      file = preview.file(),
+      identifier;
+
+  // for easy-to-scan filenames
+  identifier = caption.replace(/\s+/g, '_').replace(/\'|\"|\.|\?|\!/g, '').toLowerCase().slice(0, 20);
 
   if (!file) {
     d3.select("#row-audio").classed("error", true);
   formData.append("caption", caption);
   formData.append("citation", citation);
   formData.append("label", label);
+  formData.append("identifier", identifier);
 
   setClass("loading");
   d3.select("#loading-message").text("Uploading audio...");