Fix NSDictionaryExtend if base is `nil`

Improves NSURLConnection errors.
[Promise all] & when/all rejection handling change

`all` to match ES6. Also matches behavior by rejecting immediately when any promise is rejected.

Refs #27
Enable as many warnings as possible in tests

Tag 0.9.6
Test that HTTP errors are passed properly
Fix PromiseKit/CoreLocation subspec runtime crash

Missing selectors because that stuff didn’t get compiled in.
Promise.thenOn & don’t unleash Zalgo

Closes #1.
Fixes #22.

`then` and `catch` always execute on the main queue. `thenOn` allows you to specify a queue.

Anytime a block is executed it is done on a queue. This is so we don’t unleash Zalgo.
Fix coloration in xctest
Run lldb tests after running Sinatra
Add documentation URL
++documentation
Insist that our rejecter block takes an NSError*
[Promise description]
Improved NSError generation & handling
Don’t imply an impossible stop
RETHROW_LIKE_A_MOFO
Promise.finally; Closes #11
Starting PromiseKit+StoreKit

Based on PromiseKit+UIKit (UIAlertView).
Fixed leak

Releasing the delegate on the productsRequest:didReceiveResponse:
leaves a delegate zombie, because requestDidFinish will be called
immediately.
Added rejecter on request:didFailWithError:
Add PromiseKit/StoreKit to the Podspec

Tag 0.9.7
Returning to main queue no longer necessary

Due to thenOn, and Zalgo avoidance, the queues we are on need to subsequently be on are handled in the `then`, all that is necessary is to ensure we do as much as possible in the background.