avoid continuation lines inside macros -- they're reported as not working under MSYSdtk.
avoid continuation lines inside macros -- they're reported as not working
under MSYSdtk.

Also eliminated a multi-line substitution variable -- autoconf doesn't
like these.

FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs