Add the possibility to install BLFS tools to a running LFS from the jhalfs
menu:
- Add the possibility to choose BOOK_BLFS from menu. That hides all the
irrelevant parameters
- Adapt install-blfs-tools.sh
- Change slightly mconf.c so that there is a better alignement in menus
Unless explicitely set on the command line, the REV parameter
in BLFS tools make is the same as the preceding used one. Formerly, it
was set to sysv unless defined on the command line
