added functions to mark vertices and edges as REPEAT, INCONSISTENT and POLYMORPHIC. use functions where needed
moved TODO to DONE
fixed bug in is_edge_marked. ..._detect_cycle() delete stack if cycle is found and fixed bug with visited-array
fixed bug in ..._is_terminal(). fixed makescaffold
Merge branch 'master' of https://github.com/dorleosterode/gt-scaffold

Conflicts:
	src/gt_scaffolder_algorithms.c