Exclude dictionaries for constant storage with enum34

[fsimkovic]

The enum34 package is now distributed with CCP4. We should exchange previously converted objects back to enum34 data objects to be more consistent with how we store/access them and also comply with Python3.4 conventions.

A basic example would be the following:

class LogColors(object):
    """Color container for log messages"""
    CRITICAL = 31
    DEBUG = 34
    DEFAULT = 0
    ERROR = 31
    WARNING = 33

This would be converted to

from enum34 import Enum

class LogColors(Enum):
    """Color container for log messages"""
    critical = 31
    debug = 34
    default = 0
    error = 31
    warning = 33

Previously, we would access data using normal dict conventions, now

>>> LogColors['critical'].name
CRITICAL
>>> LogColors['critical'].value
31
>>> LogColors(31)
<LogColors.critical: 31>

What are your thoughts on this @hlasimpk?