[PATCH 00/15] perf script python: add Python3 support

[Tony Jones]

The following patches add Python3 support to the remainder of 
the scripts under scripts/python.

Minimum supported Python version is now v2.6

I tested everything against v2.7 (no patch), v2.7 (patch) and 
v3.7 (patch).  Seeteena also tested a subset (no SQL, no IPT) 
against v2.6

There are changes in order of output as key ordering is not 
consistent between v2 and v3 but format of each line should be 
unchanged.