Rule: no-sync to encourage async usage
added consistent-this rule
fixes #143
fixed broken merge
Merge pull request #144 from pigulla/master

"consistent-this" rule
Merge pull request #178 from mduvall/no-sync

Rule: no-sync to encourage async usage (fixes #177)
Rule: no-eq-null

The `no-eq-null` rule flags comparisons to null that do not use a type-checking operator.

Comparing to `null` without a type-checking operator (`==` or `!=`), can have unintended results as the comparison will evaluate to true when comparing to not just a `null`, but also an `undefined` value.

```js
if (foo == null) {
  bar();
}
```

This rule provides the functionality of JSHint's **eqnull** rule.