Refactored api for nested dehydrations.
Actualized tests.
Actualized docs in README.rst
Fixed py3-related errors in tests.
Add more tests for exceptions.
And one more test for exceptions.
Fixes for py3.2 support.
Fixes for py3 support.
Renamed test for matching by pytest.
Deleted unicode method for Exception class.
repr is str.
Merge pull request #2 from l0kix2/spec_refactor

Spec refactoring