Add Gemfile, adapt Rakefile to use port that also works on Windows, update contributing-page to reflect the proper way to run the preview, add description for Andreas
Added documentation for IDEA IDE integration
typo. replaced the "not" by "now".
added JUnit runconfiguration for IDEA
again a typo. replaced "not" by "now"
Renamed IDE section on contributing page to differentiate between using and building MapStruct