Basic BufferApp support, shows profiles in PostActivity.
Can post to BufferApp.  Closes #67.
Merge PostToAccount into ServiceRef class.  Delete PostToAccount.
Move ServiceRef up a package as it is shared between providers.
Move HttpClientFactory up a package as it is shared between providers.
Fix strangly wrapped comments.
Stop HttpClientFactory using SuccessWhaleException.
Stop BufferApp using successwhale.NotAuthorizedException.
Move ServiceRef util methods from SuccessWhaleProvider to ServiceRef.
Rename ServiceRef.enable to default.
Fix setting selected SW sub account when replying.
Move EnabledServiceRefs up a package as it is shared.
Reset enabled sub accounts when switch account.