Requiring Bourne shell for build

[Rik]

2/17/16

Mike,

I see that you recently added some changesets that add $(SHELL) to the
invocation of most scripts.  In theory, this seems appropriate because it
allows the user to override SHELL with their own tool.  In practice,
however, the build is keyed to using Bourne shell.  I happen to use tcsh so
SHELL is /bin/tcsh.  This is an exported environment variable so even if I
drop into sh first before trying to run the build system I get errors.  I
can get the build to work by doing

sh
SHELL=/bin/sh
export SHELL
bootstrap
configure
make
exit

It seems that instead of making the build platform SHELL agnostic, it is
now required to use /bin/sh for all operations.

--Rik