Use the custom wsme BooleanType on the nodes api

Instead of using a wtypes.text on the boolean types in the api and then
having to convert it, this patch uses the custom wsme BooleanType to
make the validation for it.

Change-Id: I0165c31034185beb80e50d499cb0dc67b15e45dd
Merge "Use the custom wsme BooleanType on the nodes api"