Makes "future imports" and Python version comments consistent.

This makes the "future import" statements consistently specify
absolute_import, print_function, and division, for maximum consistency
between Python 2 and Python 3.  Although absolute_import is probably a
don't care for top-level programs, if unit tests were ever implemented
for the programs they would be imported as modules, making the module
import behavior relevant.

Note that previous Python 3 fixes are a prerequisite for this change.

Also makes the "polyglot comment" consistent across sources.

TESTED:
Using a version of SConstruct patched to use the target Python for
build helpers, ran "scons build-all check valgrind-audit
www/hardware.html" with all six supported Python versions.  Also ran
gegps, gpscat, gpsprof, xgps, and xgpsspeed with both Python 2 and
Python 3.

1 files changed, 3 insertions, 2 deletions

diff --git a/jsongen.py b/jsongen.py
index f42b4017..db1f27f5 100755
--- a/jsongen.py
+++ b/jsongen.py
@@ -8,8 +8,9 @@
 # This code generates template declarations for AIS-JSON parsing from a
 # declarative specification of a JSON structure.
 #
-# This code runs under both Python 2 and Python 3. Preserve this property!
-from __future__ import print_function
+# This code runs compatibly under Python 2 and 3.x for x >= 2.
+# Preserve this property!
+from __future__ import absolute_import, print_function, division
 
 import sys, getopt