Tidying, round one of a million:

• Don't require config.h (ymo_config.h) in public includes
• Generate yimmo.h from yimmo.h.in to inject version info + get rid of
  ymo_version_*()
• Tidy up some unused vars
• Address some compiler warnings (mostly fluff, but two pointer casts
  that were only not problematic by happenstance...)
• Fix ABI ordering in configure.ac
• Bump patch level / revision ahead of next update
• Some docs updates (... and additional TODO items...)
• Ensure ymo_config.h is the first thing included in source files
• Add flexible array member hack to blalloc to work around lack of
• Fix function pointer syntax in uncrustify (FIX: tell uncrustify to
  ignore from now on + fix by hand...)
• Move ev callback typedef out of main docs...
• Misc configure.ac fixes/tidying (...and more TODO items...)