Python - ensuring backward compatibility with 2.6

[vanch3d]

On the remote server (Linux - RedHat6), only Python 2.6 is running.
So far, no chance of upgrading it to 2.7, which is the version running on both our development computers.
In the existing code, there has been a few problems to fix:

• Decimal(float) does not work, needs to take a string: Decimal(str(float))
• OrderedDict does not exist, an alternative needs to be manually installed ($pip install ordereddict). Where it was used (ea_results_v3), I've added a conditional import.
• Counter (in api_handlers) does not exist, an alternative is added to utils/ and conditional import added