Commenting and refactoring

Fixed an issue where SQL's default value for new issues was "Open"
instead of "open".
Commented javascript, API and library code.
Implemented a Deleted, DeletedBy and DeletedAt column for Issues, so
they are not deleted permanently. This is so the issue # can be
continued even if all of the issues are deleted.
Changed name of eventBus to _eventbus_ to make it more distinct.
Restructured folders.