disable eip if helper files not installed
Merge remote-tracking branch 'refs/remotes/kali/disable-eip' into develop
Update relnotes
Fold in changes
Merge branch 'release-0.5.3'
Handle undefined danger flag.
Merge remote-tracking branch 'refs/remotes/ivan/bug/handle-undefined-danger-flag' into develop
Add the flag manually if it is release version.
Merge remote-tracking branch 'refs/remotes/ivan/bug/properly-use-of-release-version-flag' into develop
Separate app.py and frontend_app.py logics.

This prepares the scenario to run the frontend and the backend in
different processes.
Add base communication framework.
Add API/SIGNALs definition.
Add license headers.
Use new frontend/backend structure in LEAP implementation.
Use new backend/signaler and start logic in processes.
Properly stop backend.
Lowercase signals names.
Do backend calls using kwargs.
Add SIGINT handler.
Add missing error/passed keys.