Remove the function kill

[rya-sge]

The function kill is removed from the baseModule
The function deactivateContract is added to the PauseModule to deactivate the contract.

Details
Add a boolean isDeactivated
A new function deactivateContract , restricted to the admin, can be used to deactivate the contract
This function set the variable isDeactivated to true.
In standalone mode, this operation is irreversible, it is not possible to rollback.
With a proxy, it is still possible to rollback by deploying a new implementation.
This function puts also the contract in the pause state
The variable isDeactivated has also an impact on the function unpause. This one will revert if the previous variable is set to true, thus the contract is in the pause state forever.

closes #210