core/build/various: python3 compat, prepare for python2 -> python3

Note 1) we're not supposed to be using #!/usr/bin/env python, see
https://fedoraproject.org/wiki/Packaging:Guidelines?rd=Packaging/Guidelines#Shebang_lines

Note 2) we're also not supposed to be using "!/usr/bin/python,
see https://fedoraproject.org/wiki/Changes/Avoid_usr_bin_python_in_RPM_Build#Quick_Opt-Out

The previous patch (https://review.gluster.org/19767) tried to do too
much in one patch, so it was abandoned.

This patch does two things:
1) minor cleanup of configure(.ac) to explicitly use python2
2) change all the shebang lines to #!/usr/bin/python2 and add them
where they were missing based on warnings emitted during rpmbuild.

In a follow-up patch python2 will eventually be changed to python3.

Before that python2-isms (e.g. print, string.join(), etc.) need to be
converted to python3. Some of those can be rewritten in version agnostic
python. E.g. print statements become print() with "from __future_ import
print_function". The python 2to3 utility will be used for some of those.
Also Aravinda has given guidance in the comments to the first patch for
changes.

updates: #411
Change-Id: I471730962b2526022115a1fc33629fb078b74338
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>

3 files changed, 3 insertions, 3 deletions

diff --git a/xlators/experimental/fdl/src/gen_dumper.py b/xlators/experimental/fdl/src/gen_dumper.py
index 42db55d2cb3..2950be44e01 100755
--- a/xlators/experimental/fdl/src/gen_dumper.py
+++ b/xlators/experimental/fdl/src/gen_dumper.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python2
 
 import os
 import re
diff --git a/xlators/experimental/fdl/src/gen_fdl.py b/xlators/experimental/fdl/src/gen_fdl.py
index d59f12a4841..136aa112861 100755
--- a/xlators/experimental/fdl/src/gen_fdl.py
+++ b/xlators/experimental/fdl/src/gen_fdl.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python2
 
 import os
 import sys
diff --git a/xlators/experimental/fdl/src/gen_recon.py b/xlators/experimental/fdl/src/gen_recon.py
index 57a5360a9f8..295df699f6e 100755
--- a/xlators/experimental/fdl/src/gen_recon.py
+++ b/xlators/experimental/fdl/src/gen_recon.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python2
 
 import os
 import re