making saving stl, amf, x3d "work" with safari. It puts the text file in...

making saving stl, amf, x3d "work" with safari.  It puts the text file in another safari window, which can be saved using ctrl-S.  What a pain!

blockscad/viewer.js

@@ -1332,8 +1332,9 @@ Blockscad.Processor.prototype = {
 
     var blob;
     if(format == "stla") {      
-      blob = this.currentObject.toStlString();        
-      blob = new Blob([blob],{ type: this.formatInfo(format).mimetype });
+      blob = this.currentObject.toStlString();      
+      // console.log("this format mimetype is:", this.formatInfo(format).mimetype); 
+      blob = new Blob([blob],{ type: "text/plain; charset=utf-8"});
     }
     else if(format == "stlb") {      
       blob = this.currentObject.toStlBinary({webBlob: true});     
@@ -1346,13 +1347,15 @@ Blockscad.Processor.prototype = {
         producer: "BlocksCAD "+Blockscad.version,
         date: new Date()
       });
-      blob = new Blob([blob],{ type: this.formatInfo(format).mimetype });
+      blob = new Blob([blob],{ type: "text/plain; charset=utf-8"});
     }  
     else if(format == "x3d") {
       blob = this.currentObject.toX3D();
+      blob = new Blob([blob],{ type: "text/plain; charset=utf-8"});
     }
     else if(format == "dxf") {
       blob = this.currentObject.toDxf();
+      blob = new Blob([blob],{ type: "text/plain; charset=utf-8"});
     }
     else {
       throw new Error("Not supported");
@@ -1362,6 +1365,9 @@ Blockscad.Processor.prototype = {
   
   supportedFormatsForCurrentObject: function() {
     if (this.currentObject instanceof CSG) {
+      // if safari, don't let them save stlb
+      if (navigator.userAgent.indexOf('Safari') != -1 && navigator.userAgent.indexOf('Chrome') == -1) 
+        return ["stla", "amf", "x3d"];
       return ["stlb", "stla", "amf", "x3d"];
     } else if (this.currentObject instanceof CAG) {
       return ["dxf"];