GNU APL now requires bash shell and in-tree builds

[Callahan, Brian Robert]

Hello --

In fixing Alexander's issue, I found these lines in the GNU APL Makefile I have 
never seen before:
buildtag.hh: Makefile buildtag.sh
        source ${top_srcdir}/buildtag.sh
        touch $@

The source command is a bash built-in and won't work on other shells, like 
OpenBSD ksh.

Additionally, even with bash, this command does not work if doing an 
out-of-tree build, which is the way I have always built GNU APL and which 
autotools are supposed to make easy to do.

Thanks.

~Brian

________________________________
Brian Robert Callahan, Ph.D.
Lecturer, ITWS@RPI
Office: Lally 304