Continued on development of 'hub' project with many refactorings/addings:

Continued on development of 'hub' project with many refactorings/addings:
- Added new exception UnexpectedPackageStatusException which will be thrown if
  the package status is not the expected one before it got 'pop-ed' from the
  stack
- Added HalfShutdownSocketVisitor which will remove the first failing entry
  from the list
- Added ability to change package status by 'pop-ing' it from the stack and
  then re-adding it
- Added (unused ATM) ConnectionRegistry which will serve for outgoing
  connections
- Many medium/minor refacturings, still there is a while() loop that needs
  refacturing to an iterator to not let the software stay to long in that
  method (which would cause other connections being paused)
- TODOs.txt updated