9. Expansion operator escape8bit, like escape but not touching newline etc..
10. Feature macros, generated from compile options. All start with "_HAVE_"
- and go on with some roughly recognisable name. Use the "-bP macros"
+ and go on with some roughly recognisable name. Option macros, for each
+ configuration-file option; all start with "_OPT_". Use the "-bP macros"
command-line option to see what is present.
11. Integer values for options can take a "G" multiplier.