updating documentation on CWTask and updating _validateExecutable
updating documentation on CWTask and updating _validateExecutable

new: -init method that if called will just set everything to be nil and generate an error on
launchTask: when called

updated: documentation on launchTask:

updated: validateExecutable no longer has a NSParameterAssert but now just checks
for a valid executable object in addition to checking that it actually exists

Machx/Zangetsu