Added comments from Marko
Pep8 cleanups
Use multiprocess support conditionally

On all python versions <= 2.6 do not run in multiprocess mode.
We see some deadlocks on RHEL6 likely due to an old matplotlib/xcb
combo so we simply disable this feature on older systems
Improve TODO
More pep8 fixes
Fixed 1 todo item
TMP
Implement proper custom graphs

Now it is possible to mix and match any metric with any indom
and all specified by regexes
Make it accept archive names without ending numbers

Suggested by Marko Myllynen
Fix the colors with custom graphs

When choosing a complex custom graph the colors are not as diverse as
they should because the number of colors is calculated without
filtering out metrics and indoms that won't end up in the graph