configure.in:
Embed the `hello world' Mercury program in the configure
script rather than compiling the one in the samples directory.
Add support for shared libraries on i386-*-freebsd*.
Makefile:
Add a Makefile which basically just forwards the work to Mmake.
This is just to make the installation sequence more standard.
INSTALL:
Modify the instructions so that they use `make' rather than `mmake'.
Mmake:
Make the `mmake clean' rule remove `config.log' and `config.status'.
Pass MMAKE_DIR rather than passing both MMAKE_VARS and MMAKE_RULES.
