Handle `@import` during CSS minification.

This meant plumbing a callback through to `compressCSS()`, which meant that
I had to alter the innards of `getFileCompressed()`. I tried to	leave that
function looking more understandable than when I found it; for example,	I
flattened out the nested `if`.

I went ahead and upgraded the version of `clean-css` while I was in the
territory.

src/node/utils/Minify.js

@@ -371,20 +371,18 @@ function requireDefinition() {
 
 function getFileCompressed(filename, contentType, callback) {
   getFile(filename, function (error, content) {
-    if (error || !content) {
+    if (error || !content || !settings.minify) {
       callback(error, content);
-    } else {
-      if (settings.minify) {
-        if (contentType == 'text/javascript') {
+    } else if (contentType == 'text/javascript') {
       try {
-            content = compressJS([content]);
+        content = compressJS(content);
       } catch (error) {
         // silence
       }
+      callback(null, content);
     } else if (contentType == 'text/css') {
-          content = compressCSS([content]);
-        }
-      }
+      compressCSS(filename, content, callback);
+    } else {
       callback(null, content);
     }
   });
@@ -400,20 +398,29 @@ function getFile(filename, callback) {
   }
 }
 
-function compressJS(values)
+function compressJS(content)
 {
-  var complete = values.join("\n");
-  var ast = jsp.parse(complete); // parse code and get the initial AST
+  var ast = jsp.parse(content); // parse code and get the initial AST
   ast = pro.ast_mangle(ast); // get a new AST with mangled names
   ast = pro.ast_squeeze(ast); // get an AST with compression optimizations
   return pro.gen_code(ast); // compressed code here
 }
 
-function compressCSS(values)
+function compressCSS(filename, content, callback)
 {
-  var complete = values.join("\n");
-  var minimized = new CleanCSS().minify(complete).styles;
-  return minimized;
+  try {
+    new CleanCSS({relativeTo: ROOT_DIR}).minify(content, function (errors, minified) {
+      if (errors) {
+        // On error, just yield the un-minified original.
+        callback(null, content);
+      } else {
+        callback(null, minified.styles);
+      }
+    });
+  } catch (error) {
+    // On error, just yield the un-minified original.
+    callback(null, content);
+  }
 }
 
 exports.minify = minify;

src/package.json

@@ -22,7 +22,7 @@
                       "express-session"         : "1.13.0",
                       "cookie-parser"           : "1.3.4",
                       "async"                   : "0.9.0",
-                      "clean-css"               : "3.4.12",
+                      "clean-css"               : "3.4.19",
                       "uglify-js"               : "2.6.2",
                       "formidable"              : "1.0.17",
                       "log4js"                  : "0.6.35",