Extend and modify the interface of matching algorithms (#265)

- Rename decomposition() to status() in MaxMatching.
- Add a new query function statusMap() to MaxMatching.
- Add a new query function matchingMap() to all the three classes.
- Rename matchingValue() to matchingWeight() in the weighted
matching classes.

#cmakedefine HAVE_LONG_LONG 1

#cmakedefine HAVE_LP 1

#cmakedefine HAVE_MIP 1

#cmakedefine HAVE_GLPK 1