Improvements in CapacityScaling.

Main changes:
- Use -potenital[] instead of potential[] to conform to the usual
terminology.
- Change the name of private members to start with "_".
- Change the name of function parameters not to start with "_".
- Remove unnecessary documentation for private members.
- Doc improvements.

 EXTRA_DIST += \

 	tools/Makefile

 if WANT_TOOLS

 bin_PROGRAMS += \

 	tools/dim_to_lgf \

 	tools/lgf-gen

 endif WANT_TOOLS

 tools_lgf_gen_SOURCES = tools/lgf-gen.cc

 tools_dim_to_lgf_SOURCES = tools/dim_to_lgf.cc