BourneShell.getExecutionPreamble does not escape the dollar sign in a directory name

`BourneShell.getExecutionPreamble` calls `unifyQuotes( dir )`, which calls `StringUtils.quoteAndEscape( path, '\"', BASH_QUOTING_TRIGGER_CHARS );`, which calls six-arg `.quoteAndEscape` in such a way that, for example, `abc$xyz` becomes `"abc$xyz"` and `.getExecutionPreamble` produces `cd "abc$xyz" && ...` which does not work because of shell interpolation of `$xyz` inside double quotes.