ref #1671 [implementing unit test for catching the bug]
'dev' -> 'issues/1671-segmentation-fault'
ref #1657 [thread optimization, bugfixes]

- thread optimization: prefix manipulations, buffer events waiting,
face wrapper locks, extensive logging
- bug fixes: debug output for FEC library, memory leaks
- code refactoring: removed usage of NDN-CPP deprecated methods
'issues/1671-segmentation-fault' -> 'dev'