Fixed memory leak when leaderboard/achievements opened multiple times.
Restructured the example.
Merge pull request #10 from wcwynn/v2.3

Fixed memory leak when leaderboard/achievements opened multiple times.
Updated the plugin and example to Cordova 2.4.
Updated the plugin and example to Cordova 2.5.
Updated the plugin and example to Cordova 2.6.
Updated the plugin and example to Cordova 2.7.
Merge pull request #11 from wcwynn/v2.7

Upgrade to V2.7