see https://review.gluster.org/#/c/19788/

use print fn from __future__

Change-Id: If5075d8d9ca9641058fbc71df8a52aa35804cda4
updates: #411
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>

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>

Replacing repetitive code like this with code generated from a more
compact "canonical" definition carries several advantages.

 * Ease the process of adding new fops (e.g. GF_FOP_IPC).

 * Ease the process of making global changes to existing fops (e.g.
   adding "xdata").

 * Ensure strict consistency between all of the pieces that must be
   compatible with each other, through both kinds of changes.

What we have right now is just a start.  The above benefits will only
truly be realized when we use the same definitions to generate stubs,
syncops, and perhaps even parts of gfapi or glupy.

This same infrastructure can also be used to reduce code duplication and
potential for error in many of our translators.  NSR already uses a
similar technique, using a few hundred lines of templates to generate a
few *thousand* lines of code.  The ability to make a global "aspect"
change (e.g. to quorum checking) in one place instead of seventy has
already been demonstrated there.

Other candidates for code generation include the AFR/EC transaction
infrastructure, or stub creation/resumption in io-threads.

Change-Id: If7d59de7a088848b557f5aea00741b4fe19017c1
BUG: 1271325
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-on: http://review.gluster.org/9411
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>