SHINDIG-1026 by Pan Jie:
1. fix empty path warning message which will cause makeRequest failure and add an unittest to reproduce this issue.
2. change SigningFetcherTest->testFetchRequestForBodyHash to use example from OAuth Request Body Hash 1.0 Draft 4
3. remove BasicGadgetSpecFactory->fetcher
4. remove GadgetOAuthTokenStore::$SERVICE_NAME and other deprecated data member
5. add setStrictNoCache() and addIdentityParams() to OAuthFetcher for code reuse
git-svn-id: https://svn.apache.org/repos/asf/incubator/shindig/trunk@767134 13f79535-47bb-0310-9956-ffa450edef68