initial commit of lint task in Makefile

Using eslint for linting.  For a complete list of rules see http://eslint.org/docs/rules/.

Here's the .eslintrc:
```
{
    "env": {
        "node": true
    },

    "rules": {
        "brace-style": [2, "1tbs"],
        "default-case": 2,  // switch blocks must always have a "default:" case
        "guard-for-in": 2,
        "space-after-keywords": [2, "always"],
        "strict": 0,  // don't require "strict mode";
        "dot-notation": 0,  // don't complain about dict["key"]
        "new-cap": 0,  // don't complain about new domTree.symboldNode()
        "no-underscore-dangle": 0,  // don't complain about _privateVariables
        "quotes": [2, "double"],
        "no-constant-condition": 0,  // don't complain about while(true)
        "no-redeclare": 0
    }
}
```