Add measurements of sizes and timings in BLFS tools

[Pierre Labastie]

This is not that easy:

• test and docs should be separated to get something useful for the book
• those instructions should be generated only for the package(s) the user wants to measure, not for all dependencies which might be pulled in
• we have to choose where the output should go: in the logs, or in a separate file named according to the package, or maybe all stats in one file

[Pierre Labastie]

Let's try an implementation with the following:

• a stat file named info-<package>.log in the work directory
• a test log file named test-<package>.log in the work directory
• a DESTDIR install (into $BUILD_DIR/dest) before the true install

Use dependencies/root.dep to get the list of requested packages, pass that list to scripts.xsl, and only generate the stat/test-log/DESTDIR instructions for those packages

I guess unless we use some new formatting in the book, separating "build/install doc" instructions from the rest will have to be done manually.

[Pierre Labastie]

Fixed at r4043. There is no way to detect doc only instructions. Test instructions have been improved. Lines have to be shuffled in script, if the order is not make; make test; make install (or same with ninja)...