Minor fix that allows for the implementation of your OAuthStore

Hi,

I've used version 175 of the client library in a WordPress plugin that 
downloads a LinkedIn&reg; profile using the LinkedIn API (LiPS). I moved from 
PECL OAuth to this library (successfully).

I didn't want to use any of the included stores since I had developed code to 
store the OAuth tokens already. So, while reading through the code, I noticed 
the OAuthStoreSession class that would require very little changes to get it 
running and, despite the warnings, I decided to extend it.

Since I'm developing my own store I assumed the file needs to be installed to 
the store directory and that's no problem. The only obstacle I encountered was 
the fact that $session in OAuthStoreSession had it's access modifiers set to 
private, so I changed the access level to protected and I'm using it. 

This issue is here to let you know I'm using this library and to ask you to 
consider this:
- Allow for an alternate installation directory for self-developed stores, by 
specifying it at construction time to keep the distribution clean.
- Change the access modifier on session to protected.

Thanks, Bas

Original issue reported on code.google.com by b...@tenberge-ict.nl on 1 Oct 2012 at 8:20

amit199222 / oauth-php

Minor fix that allows for the implementation of your OAuthStore #129