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.

 #!/bin/bash

 cd ${0%update-libstd-tag}../doc

 mv libstdc++.tag libstdc++.tag.old

 wget http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/libstdc++.tag &&

 rm libstdc++.tag.old || mv libstdc++.tag.old libstdc++.tag