Clide 127 refactor launchdelegate

Complete refactoring of the launch delegate class, as well as additional bugfixes. A notable bug fix is that before the run shortcut from the project explorer did not work, because the leading "/" was stripped from the filepath. As a result, creating a project failed (and everything thereafter). Because of this I discovered this type of errors was not caught at all, since the console still reported success despite clear failure. I made everything more robust by making the external command service throw IOExceptions, so that the LaunchDelegate can deal with them appropriately.