Integration tests of multiple connected gates and some smaller changes.
Merge pull request #22 from djqfr/master

Integration tests of multiple connected gates and some smaller changes.
Added contain method to circuit builder.
Fixed concurrency errors and fixed incorrect test cases.
Added debug flag to enable sysout messages. Defaults to false.
Added model support for importing legacy file format for simulation
Added maven support to build GUI jar file.
Added support for removing a component in a Circuit.
Added support to remove listeners from a delegator.
Removed empty line.
Merge branch 'master' of github.com:DAT055-2/OpenFlisp