added required import for PluginResult
removed last two references to callbackId
changed last use of "pr" local variable used to hold plugin result
now the source compile against cordova 2.8.1
javascript side of the plugin now uses cordova.require to be coherent with new plugin architecture.
examples will break with this, but a bwc workaround is easy to add: CDV = { FB: cordova.require('cordova/facebook/plugin') }
added missed newline at eof
Merge pull request #331 from drubbo/cordova2.8FB3.5

migrated javascript side of the plugin to cordova 2.7 architecture