Update Pylint and add explicit message template.

Example output:
```
$ pylint --rcfile=py/pylintrc py/nupic/support/enum.py
************* Module nupic.support.enum
W9820,   1: 0 - Non-executable script - script has __main__ block, but the executable bit is not set. Set the executable bit on the script or remove the __main__ block. (non-executable)
W9821,   1: 0 - Missing shebang or improper shebang (should be "#!/usr/bin/env python") for script that has __main__ block. Add the shebang line or remove the __main__ block. (no-shebang)
W0311,  30: 0 - Bad indentation. Found 6 spaces, expected 4 (bad-indentation)
C0103,  33: 0 - Invalid function name "Enum" (invalid-name)
W0212,  60:11 - Access to a protected member __labels of a client class (protected-access)
W0212,  64:18 - Access to a protected member __values of a client class (protected-access)
W0212,  68:16 - Access to a protected member __values of a client class (protected-access)
W0212,  72:16 - Access to a protected member __labels of a client class (protected-access)
W0212,  87: 2 - Access to a protected member __labels of a client class (protected-access)
W0212,  88: 2 - Access to a protected member __values of a client class (protected-access)
W0212,  88:25 - Access to a protected member __labels of a client class (protected-access)
W0611,  24: 0 - Unused import types (unused-import)
```