Add listener.ssl_certificate_id support to AWS ELB
health_check is an optional parameter for ELBs
allow vpc_zone_identifier in aws_autoscaling_group
add MapPublicIpOnLaunch
config: `module` structures parse
config: validate no duplicate modules
config: Append works with modules
config: Merge for modules works
config/module: start, lots of initial work
config/module: FileGetter tests
config/module: Get tests
config/module: test that symlink that exists will be overwritten
config: change module syntax
config/module: tree.Modules()
config/module: detectors, some more work on Tree
config/module: file paths require pwd
config: not directory that config was loaded from
config: dir on Config should be an absolute path
config/module: can load a tree properly
config/module: tree.String()