adds full support for scope customization and docs to boot
renames OAuth2_Util_Scope to OAuth2_Scope for cleaner and less annoying class names
renames Util_JWT to Encyrption_JWT to be explicit
Merge pull request #55 from F21/master

JWT's decode() now returns false instead of throwing exceptions.
Merge branch 'add-scope-storage' into develop
Merge branch 'develop' of github.com:bshaffer/oauth2-server-php into develop
after a more careful reading of the spec (and modeling github api), removes default scope default (default is now null, for 'I dont care about scope')