Update Drush & Drush Make files for qTip2

Update the Drush commands and Drush Make files to work with qTip2. The Drush command should allow for options to use the latest stable release or the nightlies, and include an option to remove the existing files prior to downloading the new ones. The Drush Make file should just grab the latest stable release but should also include a commented-out set of lines for grabbing the latest nightly build.