Update ServerTests/basic_auth.php

Fixed a small spelling mistake on line 15
added a new project for tests into the workspace
added Kiwi for testing
added some test on creating operations
added test on engine's apiPath property
added OHHTTPStubs for network requests stubbing
added tests for calling completion blocks
adding request handlers once to OHHTTPStubs
Cleaned up Demo code
updated instructions for installation via CocoaPods
Merge remote-tracking branch 'yas/adding-tests'
update Kiwi and OHHTTPStubs submodules to the latest versions
formatted TODO section in readme
prettified tests for completion and error blocks
Removed a unused +dealloc
Merge branch 'master' of github.com:MugunthKumar/MKNetworkKit
Fixed retina display support for image decompression
fixed method name in example in documantation

`setAuthorizationHeaderValue:forAuthType:`
test `registerOperationSubclass:`
added some tests for operation

test `addHeaders:`
test Authorization header
test completion blocks calls
test calls for `operationSucceeded` and `operationFilaedWithError:`