Refactor Perfdata things into pynag.Utils.metrics
Refactor GitRepo into its own module Utils.git
Refactor PynagError into Utils.errors
Refactor send_nsca into Utils.nsca
Clean up imports and linebreaks in Utils
Refactor synchronized and cache_only to decorators
Clean up imports and ordering in Utils
Refactor reconsile_threshold into Utils.metrics

+ Minor fixes
Move errors.py to top-level
Refactor reconsile_threshold>new_threshold_syntax

This function belongs there because it only supports
the new threshold syntax.

Also renamed to more approprately 'convert_to_classic_format'
Fix broken imports for errors module
Explicitly import PynagError

This is needed because there are still unresolved cross-imports
in pynag and explicitly importing PynagError fixes parts of the code
that Utils was import but at the same time those modules were doing:

'from pynag.Utils import PynagError'

This refactor, and a few other changes will make it possible for
us to get rid of those cross imports.
Merge pull request #190 from pynag/refactor

Refactor