propagate preprocessor and linker flags. This allows the programs to benefit from flags for implementing hardening. For some reason, a bunch of programs are still flagged as missing the appropriate preprocessor flags, although they are indeed passed per build log.
fix numerous useless whatis entries. Note however this is not 100% ideal in the current form, as we are patching normally autogenerated files by html2man, in particular using the script provided by upstream: src/generate_manpages.py. If this has to be forwarded upstream, then this would need further adjustment; e.g. a dictionary mapping commands with their description in the script would help with automating the production of the descriptions.
