Fix DFT visitor callback examineEdge documentation.

Author: ChrisRus

docs/algorithm-dft.md

@@ -32,13 +32,12 @@ callback | request | explanation
 initializeVertex | { u: string: g: DirectedGraph } | invoked on every vertex of the graph before the start of the search
 startVertex | { u: string: g: DirectedGraph } | invoked on the source vertex once before the start of the search
 discoverVertex | { u: string: g: DirectedGraph } | invoked when a vertex is encountered for the first time
-examineVertex | { u: string: g: DirectedGraph } | invoked on every out-edge of each vertex after it is discovered
+examineEdge | { e: { u: string, v: string },  g: DirectedGraph } | invoked on every out-edge of each vertex after it is discovered
 treeEdge | { e: { u: string, v: string },  g: DirectedGraph } | invoked on each edge as it becomes a member of the edges that form the search tree
 backEdge | { e: { u: string, v: string },  g: DirectedGraph } | invoked on the back edges in the graph. For an undirected graph there is some ambiguity between tree edges and back edges since the edge (u,v) and (v,u) are the same edge, but both the tree_edge() and back_edge() functions will be invoked. One way to resolve this ambiguity is to record the tree edges, and then disregard the back-edges that are already marked as tree edges. An easy way to record tree edges is to record predecessors at the tree_edge event point
 forwardOrCrossEdge | { e: { u: string, v: string }, g: DirectedGraph } | invoked on forward or cross edges in the graph. In an undirected graph this method is never called
-finishEdge | | invoked on each non-tree edge as well as on each tree edge after finish_vertex has been called on its target vertex
 finishVertex | { u: string: g: DirectedGraph } |invoked on vertex u after finish_vertex has been called for all the vertices in the DFS-tree rooted at vertex u. If vertex u is a leaf in the DFS-tree, then the finish_vertex function is called on u after all the out-edges of u have been examined.
-
+finishEdge  | { e: { u: string, v: string },  g: DirectedGraph } | invoked on each non-tree edge as well as on each tree edge after finishVertex has been called on its target vertex
 
 **See also: [Boost C++ Graph Library: DFS Visitor Concept](http://www.boost.org/doc/libs/1_55_0/libs/graph/doc/DFSVisitor.html)**