Add `has` method for checking is a deferred exists
Clean up state methods, add convenience methods

This uses Deferred.state() internally since isRejected and isResolved
are deprecated since 1.7. This may be a bad idea to use these methods
in this API if they are deprecated in jQuery..
Implement manage and unmanage methods, update reset

`manage` enables using promiser with deferred objects created by other
means such as `$.ajax()` or manually using `$.Deferred`.

`unmanage` enables removing a deferred object from promiser and
returning it. In case a deferred needs to simply go away, simply
call unmanage to deference it so it falls out of scope.

`reset` has been update to use `unmanage` internally and no longer
enforces the deferred to be not pending. The difference between reset
and unmanage is that `reset` returns the promiser object and unmanage
returns the (now) unmanaged deferred.

Close #4
Increase minimum jQuery version to 1.7

always() was introduced in 1.6
state() was introduced in 1.7
Implement the watch method

This provides a way for handlers to execute when the deferred is
initially created. For example, an ajax request should not occur, unless
the data will be used on response. The first time a deferred is 'bound'
to via done, then, fail, or always, the watch handlers will be executed
once.

Close #5
Fix typo
Add Grunt and Jasmine tests

Close #1
Add package.json for NPM

Close #3
0.2.0 Release