Editing one new rocktype's permeability cause all new rocktypes' permeability

[Angus Yeh]

In the rocktype editing table, if users added a few rocktypes, then change one of rocktype's permeability. Then all new rocktypes' permeability will change as well. This however does not happen when changing porosity!

[Angus Yeh]

This is caused by using rocktyp() to create rocktype with default permeability. See http://docs.python-guide.org/en/latest/writing/gotchas/#mutable-default-arguments

[Angus Yeh]

This is resolved by newer PyTOUGH, see commit https://github.com/acroucher/PyTOUGH/commit/4b48b666c4a32855ab67985975cdecc7499609d8

[Angus Yeh]

Use PyTOUGH after commit 4b48b666c4a32855ab67985975cdecc7499609d8