Bug 470455 - Difficulty in creating associations

Caused by too strict check for avoiding creation of connections starting
from the diagram root (see
https://bugs.eclipse.org/bugs/show_bug.cgi?id=424020).

* Removed that check again
* Introduced new fix (prevent anchor creation on diagrams instead of not
allowing connection start when there is no anchor on current PE)
* Added test for usecase

Change-Id: I7d47f14f5ca42a2ac2546059d8d70c1317358d16
4 files changed
tree: b3ceedc9898d20f809e4bc15d7a0cd7057753293
  1. CONTRIBUTING.md
  2. examples/
  3. features/
  4. parent/
  5. plugins/
  6. releng/
  7. tests/