Decoupled platforms

Platforms are in their own package now. NB: this requires a different way of installing! Please use the vagrantbox in the dropbox. By hand you could do this (from the crowd-watson root dir):

echo "--- Installing Crowdflower package ---"
cd workbench/cw/crowdflower/
sudo composer install
sudo cp /vagrant/configurations/crowdflower/config.php src/config/config.php # change this

echo "--- Installing mTurk package ---"
cd ../mturk/
sudo composer install
sudo cp /vagrant/configurations/mturk/config.php src/config/config.php # change this
cd ../../..
sudo composer install
sudo php artisan dump-autoload

* Known bugs:
Although the annotations are saved correctly,
- Not all the results from crowdflower are saved in the job results vector
- AMT doesn't seem to save any Job results in the vector (this is a minor issue, will be fixed this week)