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

if WANT_TOOLS

bin_PROGRAMS += \

	tools/dimacs-to-lgf

dist_bin_SCRIPTS += tools/lemon-0.x-to-1.x.sh

endif WANT_TOOLS

tools_dimacs_to_lgf_SOURCES = tools/dimacs-to-lgf.cc