#965 PLCgen: iteration limit is bounded response property + 1, and fix loop killed condition.

• Best to review per commit.
• End-user visible changes:
  • PLCgen: Iteration limit is bounded response property + 1. Terminology-wise, the limit is now what is used (in the code), while the bound is what is computed (in the annotation). The limit is thus no longer the same as the bound.
  • PLCgen: A loop is only killed if the last iteration had progress. That is, if no event was executed in the last iteration, the loop is no longer registered as having been killed.
  • PLCgen: Improved some warning messages related to controller properties annotation.
  • PLCgen: Improved 'PLC maximum iterations' option description and error message.
  • PLCgen: Improved 'PLC maximum iterations' option documentation:
    • Updated for changes of this branch.
    • Small textual improvements.
    • inf is not unique in allowing one iteration more than the computed bound.
• Other changes:
  • Improved some JavaDocs/comments.

Closes #965 (closed)