Update MatchingOneOrMoreRepetitions.py

Update MatchingEndingItems.py

Update MatchingAnythingButANewline.py

Update Matching-Word-Boundaries.py

Update ForwardReferences.java

Update Capturing&Non-CapturingGroups.py

Update BranchResetGroups.php

Update BackreferencesToFailedGroups.py

Update AlternativeMatching.py

Create NegativeLookbehind.py

Create PositiveLookbehind.py

Create NegativeLookahead.py

Create ForwardReferences.java

Create BranchResetGroups.php

Create BackreferencesToFailedGroups.py