Cleaned up local variables
Use isRegExp in Assertion::throwException. Fix #25
Exposed object stringification function

This will be useful for people extending expect.js with their own assertions
Ignore 'script*' global leak in chrome
Pass .fail() unit test
Add 'actual' & 'expected' property to the thrown error
Use 'showDiff' flag
Better to follow the same coding style
Add support for 'regexp' type and eql comparison of regular expressions.
Added formatting for Error objects

Printing an error object from node.js generates an unhelpful `{}` response.

~~~
var e = new Error("Something went bad");
expect(e).to.be(null); // Prints Error: expected {} to equal null
~~~

Passing the response through toString gives a nicer result:

~~~
Prints Error: expected [Error: Something went wrong] to equal null
~~~
eql(): fix wrong order of actual vs. expected.

The helper `expect.eql()` function, like typical assertion methods,
takes `actual` then `expected`:

https://github.com/LearnBoost/expect.js/blob/master/expect.js#L850

But the `Assertion.prototype.eql` wrapper has been incorrectly
passing `this.obj` (the object being tested) as the `expected`, and
vice versa passing `obj` (the object used for comparison) as the
`actual`. This fixes that.
Merge pull request #56 from aseemk/patch-1

eql(): fix wrong order of actual vs. expected
Merge pull request #52 from mikeando/master

Addition of formatting for Error objects.
Merge pull request #46 from bramstein/bs-add-regexp

Add support for 'regexp' type and eql comparison of regular expressions.
Merge pull request #34 from curvedmark/mocha-diff

Add 'actual' & 'expected' property to the thrown error
Merge pull request #17 from tricknotes/cleanup

Cleaned up local variables
Merge pull request #26 from amasad/fix-25

Use isRegExp in Assertion::throwException. Fix #25
Merge pull request #29 from nathanmacinnes/master

Expose object stringification function `i`
Add .withArgs() syntax for building scenario

Makes it easy to test that a function validates its inputs.