Add the EnvUser with tests. Create an Environment user during bootstrap

Added the EnvUser doc

Support for setting the last login time for the EnvUser

Added a factory for adding the envuser

Admin EnvUser gets added at bootstrap time

Removed a couple of attributes from the upgrade package that no longer needed to be there

The idea behind this and the other factory methods are to initialise units/ services/ machines for use in tests. Sometimes you don't need to specify the attributes - sometimes you do. The vParams is so that you can call factory.MakeEnvUser() meaning. "Make an EnvUser but I don't care how the field get populated. Itsaves the user having to call factory.MakeEnvUser(nil) which makes the tests a little neater