fix yaml parsing:  multiple tags must be space-separated, not comma-separated

was ignoring the tag to inform Unmarshall the name of the field for yml
allow the dockerfile specification to use environment vars
When status command fails, print more debug info
Merge pull request #11 from rliebling/fix_yaml_parsing

Fix YAML parsing: multiple tags must be separated by space, not comma
Merge pull request #12 from rliebling/allow_env_vars_for_dockerfile

allow the dockerfile specification to use environment vars
Bump version to 0.6.1
Move print functions into their own package
Move command handling into cmd.go
Use long option names

Short names such as `-rm` are deprecated as of Docker 0.9.
add option to specify config file

allows one to have multiple configuration files (json/yml) in same dir
and select which to use via cmdline option
rename Config type to Options, and the variables too

Better name to represent the cmdline options
docker parameter is --hostname not --host
Cleanup config file handling: rename manifestFiles, fix default

mostly cleanup, but also fixed the defaults to include crane.yml
instead of repeating crane.json twice.
Merge pull request #17 from gissehel/hostname

docker parameter is --hostname not --host
Merge pull request #15 from rliebling/allow_alternate_config_file

Allow option to specify config file
Merge pull request #14 from rliebling/show_errors_for_status

When status command fails, print more debug info