Fix repl and other misc code, including test

[michalz-zoom]

• At some point Node.js repl.rli was deprecated. Properties of 'rli' were already present in 'repl' REPLServer object, so this is a simple change.
• Fix Buffer constructor calls which are deprecated.
• Fix other test files, again, mostly Node libraries changing things around (changes in vm.Script, fs.unlink, assert.throws etc.)
• In Cakefile, be more verbose where the global functions come from ('assert' module - ok, fail etc.), also add a way to run single (or multiple) test files instead of full test suite.