Quick proposal: remove exceptions from Roller.getXXXManager() methods

[Allen Gilliland]

I've started notice a little nit pick that I have about the fact that we 
throw a RollerException from all of the Roller.getXXXManager() methods. 
 I find myself constantly feeling that this is a totally useless 
exception which often causes the code to be overly littered with 
try/catch blocks which ultimately have no real use.

Would anyone object to changing these methods to not throw an exception? 
 Does anyone see any value in having these methods throw that exception?

Also, just to be clear, this work wouldn't be done until after the 3.1 
release is finalized.

-- Allen