* Add a DeployConfiguration class to hold settings related
   to deployment.
 * Add BuildStepsList to hold a list of buildsteps
 * Update BuildConfiguration to use BuildStepLists instead of
   manageing lists of buildsteps itself.
 * Update BuildManager to use BuildStepLists in its interfaces
 * Fix fallout introduced by API changes
 * Update .user file to new way of storing settings

Task-number: QTCREATORBUG-1427
Task-number: QTCREATORBUG-1428
Task-number: QTCREATORBUG-1811
Task-number: QTCREATORBUG-1930