[M3devel] New compile failure

[Rodney M. Bates]

The compiler in the head, with some recent changes, gives:

rodney at yellowstone:~/proj/m3/cm3-head/cm3/m3-sys/m3middle$ cm3

Fatal Error: configuration file didn't specify BUILD_DIR

This message is coming from cm3/src/Main.m3, which has recently
changed, but there are related changes to other source files
too.  Reverting Main.m3 to the previous version won't compile.

Putting an older executable for cm3 into the bin directory,
with recently updated and installed cm3.cfg and config works.