[WIP] Python 2+3 support.

Add six, convert PY <=2.5 exception handling, dictionary iteration, libraries, 1/2 the tests.
[WIP] Python 2+3 support.

Add six, convert PY <=2.5 exception handling, dictionary iteration, libraries, remaining 7/8 test modules.
[WIP] Python 2+3 support.

maxint and minor additions.
Merge branch 'develop' of https://github.com/theupdateframework/tuf into develop

Conflicts:
	tuf/__init__.py
	tuf/client/updater.py
[WIP] Python 2+3 support.

Python 2+3 unicode.
libraries.
The following modules (and their tests) work in PY2.7+3.3:
keydb, hash, formats, mirrors
[WIP] Python 2+3.

Mostly unicode-related changes for crypto modules.
Merge branch 'develop' of https://github.com/theupdateframework/tuf into develop

Conflicts:
	tests/test_hash.py
	tests/test_keydb.py
	tuf/formats.py
	tuf/keydb.py
	tuf/repository_tool.py
[WIP] Refactor download.py
Finish initial refactor of slow retrieval attack.
Finish unit tests for Python2 + 3 support.

All unit tests updated / running for Python 2 + 3.
TODO: Fix non-Python 3 issue with util.py.
Update slow retrieval server and fix integration tests.

Update the slow retrieval server, integration tests, and the download module to address issues with unexpected exceptions and bytes.
Address Python 3.2 byte-string compatibility issues.
Improve test coverage.

Update unit tests for pycrypto_keys, schema, ed25519_keys, and affected modules.
Re-generate repository data.
Refactor repository_tool.py and improve test coverage.

Created repository_lib.py.
Update repository tool diagram and coverage.

Fix text box alignment in diagram.
Omit coverage of repository tool prompt and getpass.
Minor coverage update.
Fix Python 2 + 3 JSON consistency issue and re-generate repository data.

Explicitly specify the JSON separators for Python 2 + 3 consistency.
Fix test_util.py test case failure in py2.7.
Increase sleep time after starting simple server in affected tests.
Merge branch 'develop' of https://github.com/vladimir-v-diaz/tuf into develop