Disable job script stuff by default to restore old behavior if not using job script extension.

Author: jmchilton

cwltool/job.py

@@ -26,7 +26,7 @@
 
 needs_shell_quoting_re = re.compile(r"""(^$|[\s|&;()<>\'"$@])""")
 
-FORCE_SHELLED_POPEN = os.getenv("CWLTOOL_FORCE_SHELL_POPEN", "1") == "1"
+FORCE_SHELLED_POPEN = os.getenv("CWLTOOL_FORCE_SHELL_POPEN", "0") == "1"
 
 SHELL_COMMAND_TEMPLATE = """#!/bin/bash
 python "run_job.py" "job.json"