utils.FakeAdagiosEnvironment added

This class is in the style of pynag.Utils.misc.FakeNagiosEnvironment
and is meant to help with creating isolated environments for adagios
testing.

I think this be a big help with future unit testing, especially in
the web api.

Highlights of this commit:

* New method: utils.reload_config_file() which updates
  adagios.settings in runtime

* New class utils.FakeAdagiosEnvironment() which helps
  with testing

* Unit tests for misc.tests.MiscTestCase were updated
  to always run in an isolated environment

* Issue #361