IMPALA-9627: Update utility scripts for Python 3 (part 2)

We're starting to see environments where the system Python ('python') is
Python 3. Updates utility and build scripts to work with Python 3, and
updates check-pylint-py3k.sh to check scripts that use system python.

Fixes other issues found during a full build and test run with Python
3.8 as the default for 'python'.

Fixes a impala-shell tip that was supposed to have been two tips (and
had no space after period when they were printed).

Removes out-of-date deploy.py and various Python 2.6 workarounds.

Testing:
- Full build with /usr/bin/python pointed to python3
- run-all-tests passed with python pointed to python3
- ran push_to_asf.py

Change-Id: Idff388aff33817b0629347f5843ec34c78f0d0cb
Reviewed-on: http://gerrit.cloudera.org:8080/19697
Reviewed-by: Michael Smith <michael.smith@cloudera.com>
Tested-by: Michael Smith <michael.smith@cloudera.com>

lib/python/impala_py_lib/jenkins/generate_junitxml.py

@@ -21,12 +21,13 @@ A script for generating arbitrary junit XML reports while building Impala.
 These files will be consumed by jenkins.impala.io to generate reports for
 easier triaging of build and setup errors.
 """
-from __future__ import print_function
+from __future__ import absolute_import, division, print_function
 import argparse
 import codecs
 import errno
 import os
 import re
+import sys
 import textwrap
 from xml.dom import minidom
 from xml.etree import ElementTree as ET
@@ -167,7 +168,10 @@ class JunitReport(object):
     junit_log_file = os.path.join(junitxml_logdir, filename)
 
     with codecs.open(junit_log_file, encoding="UTF-8", mode='w') as f:
-      f.write(unicode(self))
+      if sys.version_info.major < 3:
+        f.write(unicode(self))
+      else:
+        f.write(str(self))
 
     return junit_log_file
 
@@ -212,7 +216,10 @@ class JunitReport(object):
     else:
       # This is a string passed in on the command line. Make sure to return it as
       # a unicode string.
-      content = unicode(file_or_string, encoding="UTF-8")
+      if sys.version_info.major < 3:
+        content = unicode(file_or_string, encoding="UTF-8")
+      else:
+        content = file_or_string
     return JunitReport.remove_ansi_escape_sequences(content)
 
   def __unicode__(self):
@@ -223,6 +230,10 @@ class JunitReport(object):
     root_node_dom = minidom.parseString(root_node_unicode)
     return root_node_dom.toprettyxml(indent=' ' * 4)
 
+  def __str__(self):
+    if sys.version_info.major < 3:
+      return unicode(self).encode('utf-8')
+    return self.__unicode__()
 
 def get_options():
   """Parse and return command line options."""

lib/python/impala_py_lib/jenkins/junitxml_prune_notrun.py

@@ -21,6 +21,7 @@
 Some tests that produce JUnitXML include tests that did not run (i.e. status="notrun").
 This script walks through the JUnitXML and removes these elements.
 """
+from __future__ import absolute_import, division, print_function
 from optparse import OptionParser
 from xml.etree import ElementTree as ET
 from xml.dom import minidom