Re-add Python 2 compatibility code HTCONDOR-549

When the blahp is installed as a user from a tarball, we can't guarantee
that Python 3 is installed on the system. So restore the Python 2
compatibility code for systems where Python 3 isn't available in the
base OS install.

src/scripts/blah.py

@@ -1,7 +1,11 @@
 """Common functions for BLAH python scripts"""
 
-from configparser import RawConfigParser
-from io import StringIO
+try:  # for Python 2
+    from ConfigParser import RawConfigParser
+    from StringIO import StringIO
+except ImportError:  # for Python 3
+    from configparser import RawConfigParser
+    from io import StringIO
 
 class BlahConfigParser(RawConfigParser, object):
 

src/scripts/lsf_status.py

@@ -31,6 +31,8 @@
 for subsequent queries.
 """
 
+from __future__ import print_function
+
 import os
 import re
 import pwd

src/scripts/pbs_status.py

@@ -28,6 +28,8 @@
 for subsequent queries.
 """
 
+from __future__ import print_function
+
 import os
 import re
 import pwd

src/scripts/slurm_status.py

@@ -28,6 +28,8 @@
 will reuse this for subsequent queries.
 """
 
+from __future__ import print_function
+
 import os
 import re
 import pwd