Set SCHEME to gambit and update book.gsi target to load gambit/book.scm.
Add write permissions so interpreters can be updated by make.
Add mkdir as dependency for interpreter targets.
Add the -:s runtime option so that syntax-case is available.
Remove old syntax-case code and just use builtin define-syntax everywhere.
Set stderr-port to (current-error-port).
Fix get-internal-run-time.
Move definition of tester-error before inclusion of format.scm
Define support-error and temporarily comment out show and clone.
Replace ##dynamic-let with with-exception-handler.
Set-gc-report is now called gc-report-set!.

Also, don't enable gc-report by default.
Copy define-meroonet-macro from bigloo/hack.bgl.

It seems meroonet-macros expect to be defined via define-macro, rather
than define-syntax.
Add GSC variable and remove heap size restriction.
Add changes to compile book.gsc, with a note about gsc -:s breakage.
Add note about gsc/ghostscript naming conflict.
Fix test.chap4. Gambit complians about invalid infix syntax for TeX command \ldots.
Fix test.chap5f. Add a GENSYM that accepts a string argument.
Fix test.chap6f. Add FLUSH-BUFFER and SYSTEM procedures.

Note that test.chap6f still fails on continuations used out of their
dynamic extent, as mentioned in the Makefile.
Don't try to DEFINE toplevel procedures in macro expansion.

Gambit doesn't bind the symbols in the toplevel env, but rather in the
lexical env of the macro.

Bind the symbols to wrong initially and SET! them to the correct
definition at the end of the expansion of define-instruction-set.

Fixes test.chap7{d,e,g,h,i} and test.chap8{d,h,i} and evalf.test.chap8f.
Gambit complains about an invalid-escaped-character for \<.