providers/aws: resource_aws_instance partially to schema.Resource
helper/schema: can set conninfo
helper/schema: if no ID is set then return nil
helper/schema: add GetOk
helper/schema: add support for StateFunc
fmt
providers/aws: use StateFunc to process the user_data
helper/schema: When having a StateFunc, make sure NewExtra contains
original
helper/schema: store state with processed properly
helper/schema: don't mark things computed if an ID is set
providers/aws: fix some other issues with aws_instance
Merge pull request #220 from hashicorp/f-aws-instance-schema

aws_instance to helper/schema, and fixes for helper/schema