Port DIMACS tools from svn -r3516

Namely,
- apply migrate script
- apply unify sources
- break long lines
- Fixes the compilation
- dim_to_lgf -> dimacs-to-lgf
- better .hgignore
- shorten the doc of dimacs-to-lgf

/* Define to 1 if you have CPLEX. */

#undef HAVE_CPLEX

/* Define to 1 if you have GLPK. */

#undef HAVE_GLPK