Moved some files to be 2.0 compatible

Hi there,

I've updated your Twitter plugin, so it is compatible with the upcoming CakePHP 2.0 release. It mostly involved renaming folders, but I've also updated some App::import() calls.

I've put my changes in a separate branch, since they're not backward compatible with 1.3 and below. But I'm not sure if this pull request puts my changes in a separate branch as well.


Bjorn