Update AFOAuth1Client/AFOAuth1Client.m

Allows to use oAuth without token (using only consumer key)
In Flickr OAuth implementation, 'oauth_token_secret' key is returned after 'oauth/request_token' request. The key is needed for signing 'oauth/access_token' request later and this commit attempts to fix it.

The current AFOAuth1Client implementation only assign `accessToken` after 'oauth/access_token' request. This may work for Twitter, but this will not work for Flickr.
The signing method looks for `accessToken` when attempting to build the secret key needed, so we had to wrap the following logic by temporary assigning `accessToken` with `requestToken` to trick the signing method to sign with the correct key.
After making this change, I ran the sample code and it seems to work well for twitter as well.
Flickr OAuth implementation are done through GET parameters instead of request header. Another fixed for Flickr OAuth implementation.

The URL are not built with the modified parameters (although its Authorization header is built with modified parameters).
This will not work for Flickr because its implementation depends on the query of the URL instead of the Authorization header.

Reference: http://www.flickr.com/services/api/auth.oauth.html
Adding comma (,) as a percent escaped character since it's in the reserved words per the RFC
Add two-legged auth support

Adds two legged auth support by being smarter about picking up auth parameters from the request or building them on the fly.

Fixes the broken behavior of adding all parameters to the Authorization header
Added multipartFormRequest and refactored auth header
Merge pull request #22 from lxcid/master

Fixes for Flickr OAuth implementation.
Merge pull request #18 from shir/patch-1

Allows to use oAuth without token (using only with consumer key)
Merge branch 'bug/two-legged' of git://github.com/madninja/AFOAuth1Client into madninja-bug/two-legged

Conflicts:
	AFOAuth1Client/AFOAuth1Client.m
Merge pull request #25 from madninja/bug/percent-escapes

Adding comma (,) as a percent escaped character
Merge branch 'master' of https://github.com/AFNetworking/AFOAuth1Client

Conflicts:
	AFOAuth1Client/AFOAuth1Client.m
Merge branch 'authheader' of git://github.com/pj4533/AFOAuth1Client into pj4533-authheader

Conflicts:
	AFOAuth1Client/AFOAuth1Client.m
[Issue #17] Setting accessToken to requestToken in -acquireOAuthAccessTokenWithPath:requestToken:accessMethod:success:failure:
Updating version to 0.1.1
Added an optional scope parameter for getting a request token per https://developers.google.com/accounts/docs/OAuth_ref#RequestToken. Should not affect existing code.
Unregister as observer on  application launch notification in notification block
Unregister from notifications on dealloc. Handle case where there is a dangling notification observer still registered when a user cancells the sign-in
moved unregister notification to end of block
Updates requestWithMethod:path:params to not use post or query params. Updates authorization request to use query params.
Renamed unregisterFromApplicationLaunchNotifications to removeApplicationLaunchNotificationObserver