Adding basic type checking

@dpup @skuwamoto @eford1 - adding basic type checking to shepherd (configurable)

Hello dan, eford, sho, 

Please review the following commits I made in branch 'azulus-types'.

774225526866c37d95aebc437162de3dd3377b7c (2013-04-23 10:29:20 -0700)
Adding type checking

aa3fd0dd60728ff3c165ee64fc862512a5dd7e57 (2013-04-22 15:01:36 -0700)
Added object test

66f96e80389299a5108efe46079b3dde5ed4b3e5 (2013-04-22 14:59:51 -0700)
Added bool test

7b324f2821b6c987e53637fcd0e76c14da37fd04 (2013-04-22 14:56:49 -0700)
Building out type tests

R=dan
R=eford
R=sho