Improved transforms

Transforms are now only cached until the source file changes,
and the extension argument now expects a period (i.e ".html")
to be consistent with the path.extname function.

README.md

 ```
 var sass = require("node-sass");
 
-app.transform("sass", "text/css", (path, writeStream) => {
+app.transform(".sass", "text/css", (path, writeStream) => {
 	try {
 		var str = fs.readFileSync(path, "utf8");
 	} catch (err) {
 Now, any .sass file served with `webframe.static` will be compiled into CSS,
 and sent with the browser with the MIME type "text/css". The result is also
 cached, so the expensive sass compilation will only happen the first time the
-file is requested. The result will not be cached if you call writeStream.error.
+file is requested, or when the file changes. The result will not be cached
+if you call writeStream.error.

example.js

 
 // Endpoint which uses the "params" middleware to parse URL parameters
 app.get("/params-example", [ mw.params ], (req, res) => {
+	res.writeHead(200, { "Content-Type": "text/plain" });
 	res.end("Hello, "+req.params.name);
 });
 
 // Endpoint which uses the "payload" middleware to get the payload as a string
 app.post("/payload-example", [ mw.payload ], (req, res) => {
+	res.writeHead(200, { "Content-Type": "text/plain" });
 	res.end(req.payload);
 });
 

js/static.js

 }
 
 var transformCache = {};
-function handleTransform(path, req, res, app) {
-	var ext = pathlib.extname(req.url).substring(1);
+function handleTransform(stat, path, req, res, app) {
+	var ext = pathlib.extname(path).substring(1);
 	if (ext === "")
 		return false;
 
 
 	if (transformCache[path]) {
 		var c = transformCache[path];
-		res.writeHead(c.status, c.headers);
-		res.end(c.content);
-		return true;
+		if (stat.ctime === c.ctime) {
+			res.writeHead(c.data.status, c.data.headers);
+			res.end(c.data.content);
+			return true;
+		} else {
+			console.log("throwing out because ctime.");
+			delete transformCache[path];
+		}
 	}
 
 	var data = { content: "", headers: null, status: null };
 			if (!nocache) {
 				data.status = writeStream.status;
 				data.headers = writeStream.headers;
-				transformCache[path] = data;
+				transformCache[path] = {
+					data: data,
+					ctime: stat.ctime
+				};
 			}
 		},
 
 		// Join the web root with the request's path name
 		var path = pathlib.join(root, pn.replace(before, ""));
 
-		// If there's a transform, let that handle it
-		if (handleTransform(path, req, res, app))
-			return;
-
 		// Send a file
 		function send(path) {
 			sendfile(path, app, pn, req, res);
 				path = pathlib.join(path, "index.html");
 			}
 
-			// Send the file
+			// If there's a transform, let that handle it
+			if (handleTransform(stat, path, req, res, app))
+				return;
+
+			// Otherwise, send the file
 			send(path);
 		});
 	}

package.json

 {
   "name": "webframe",
-  "version": "0.7.0",
+  "version": "0.8.0",
   "description": "Web framework.",
   "main": "index.js",
   "scripts": {