Detail:
  The romlinker joiner format is now defined and implemented by srcbuild.
    This means that srcbuild can invoke romlinker to join main ROMs,
    expansion ROMs or extension ROMs depending on a switch in a product's
    components file (the %format directive should specify a value of one
    of rom extrom or exprom).
  Any %-directives that are not srcbuild directives are passed through to
    romlinker as command-line options.  All target image sizes are passed
    through in bytes - see romlinker documentation for full details of the
    interfaces.
  Environment variables are set to represent the territory mappings.  This
    is done on all targets so that other tools can rely on retrieving the
    information via getenv() and not needing to prod the International
    module directly.
  extern declarations removed from .c files into .h files to remove chance
    of mismatched multiple declarations.
  Some spelling corrections in comments, system call synchronisation calls
    added, although sb_system does not implement parallel makes yet.
  Documentation added on the portability aspects, environmental aspects and
    the territory mapping stuff.  A program is provided (MkDefaults) to
    run under RISC OS to generate up-to-date source code for srcbuild's
    territory information database.
  srcbuild now keeps note of the type of image that it is generating, rather
    than relying on reverse-engineering it from the joiner and joiner format
    strings (set by %format in the component file, defaults to main ROM)
  Many comments updated to reflect the actual code, some obsolete code
    removed.
Admin:
  This version should represent a functionally complete version capable of
    running cross-compiled builds on UNIX systems.
  Tested on RISC OS.

Version 0.27. Tagged as 'srcbuild-0_27'