capture stdout from call responses,
strip out private SUPERCOLLIDERJS messages
sclang-interpret: add postErrors option to post Error.reportError to stdout
nowExecutingPath: fix resetting previous,
don't path to SyntaxError (unneeded, breaks stdout capture)
use standard class names in js doc strings
JSON conversion for Class -> "Class", fixes broken JSON
fix for classic mode
sclang-evaluate: getBacktrace
sclang getBacktrace add function sourceCode for args
sclang-interpret: parse syntax errors from STDOUT