Add --continue-on-collection-errors option to restore the previous behaviour:
Execute tests (that were successfully collected) even when collection errors
happen.
Some tests had to be modified e.g. because the return code changed to 2
(EXIT_INTERRUPTED) instead of 1 (EXIT_TESTSFAILED) because an Interrupted
exception is raised on collection error.
Implemented via pair programming with:
Oleg Pidsadnyi <oleg.pidsadnyi@gmail.com>
closes#1421