Compile LESS on `npm run build:watch` and LESS file changes

vs. compiling only on LESS file changes

scripts/less-watch

@@ -15,6 +15,17 @@ var fs = require('fs');
 var path = require('path');
 var child_process = require('child_process');
 
+function printResults(err, stdout, stderr) {
+  if (err) return console.log(err);
+  if (stdout) console.log(stdout);
+  if (stderr) console.log(stderr);
+}
+
+function compileLESS() {
+  child_process.exec('lessc --include-path=notebook/static --verbose notebook/static/style/style.less notebook/static/style/style.min.css', printResults);
+  child_process.exec('lessc --include-path=notebook/static --verbose notebook/static/style/ipython.less notebook/static/style/ipython.min.css', printResults);
+}
+
 function watchDir(dir) {
   var rootPath = path.join(__dirname, '..');
   var watchPath = path.resolve(dir);
@@ -22,18 +33,10 @@ function watchDir(dir) {
   fs.watch(watchPath, {recursive: true}, function(event, file) {
     if (file && /.+\.less$/.test(file)) {
       console.log('less-watch:', 'modified:', file);
-      child_process.exec('lessc --include-path=notebook/static --verbose notebook/static/style/style.less notebook/static/style/style.min.css', function(err, stdout, stderr) {
-        if (err) return console.log(err);
-        if (stdout) console.log(stdout);
-        if (stderr) console.log(stderr);
-      });
-      child_process.exec('lessc --include-path=notebook/static notebook/static/style/ipython.less notebook/static/style/ipython.min.css', function(err, stdout, stderr) {
-        if (err) return console.log(err);
-        if (stdout) console.log(stdout);
-        if (stderr) console.log(stderr);
-      });
+      compileLESS();
     }
   });
 }
 
+compileLESS();
 watchDir(process.argv[2]);