Removed optimizations in ca4073a.

References may be a thing down the line - could they be replaced with direct usage at thr bytecode level?

From #133

Duplicate strings in bytecode.

Removing the assertion checks, see #145 .

Done, and controlled via a command line switch to the repl.

Removing scope-pushes in single-line blocks?

if (x) {
    print "foo";
}

In this case, pushing and popping a scope isn't needed. If something is declared, then you'd still need a scope.