auto-generate package/Config.in

auto-generate package/Config.in

The algorithm in package/pkgmaker works as follows:
1) for all package/*/Makefile
  a) parse PKG_NAME and PKG_SECTION
  b) skip if PKG_SECTION is 'kernel' (special ones)
  c) check if Config.in{,.lib,.manual} contain something
  d) fetch the first word of the first prompt from any result from c)
  e) fetch the verbose section name from package/SECTIONS.list based on
     PKG_SECTION, or just 'libs' if it's about Config.in.lib
  f) write results to package/package_section_list, in the form:
   '<Config.in prompt> <path to Config.in file> <verbose section name>'
2) sort package/package_section_list first by <verbose section name>,
   next by <Config.in prompt>
3) create package/Config.in.auto using the result from 2)