Load dygraph-combined when loading from NPM

Today, when loading dygraphs from NPM via browserify you need to include:

```javascript
var Dygraph  = require('dygraphs/dygraph-combined.js');
```

Being able to do this:
```javascript
var Dygraph  = require('dygraphs');
```

Is preferable.

diff --git a/package.json b/package.json
index 82d961b..0b04689 100644 (file)
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "dygraphs",
   "version": "1.1.0",
   "description": "dygraphs is a fast, flexible open source JavaScript charting library.",
-  "main": "dygraph.js",
+  "main": "dygraph-combined.js",
   "directories": {
     "doc": "docs",
     "test": "tests"