common: Add CheckTemplates which checks all strings if valid templates
common: Template is a struct for state reasons
common: tests for NewConfigTemplate
common: ConfigTemplate.Process can in-place modify
common: properly replace user/builder vars
common: errors while processing
common: don't prepend '.' on keynames of template keys
common: key names prefer mapstructure tag
common: better docs for the TemplateCOnfig
common: step to process config templates
common: testing embedded structs to be sure for templates
common: add "timestamp" function to template for unix timestamp
common: ignore unexported fields in template processing
builder/digitalocean: use common templates to process all strings
command/fix: fix snapshot_name in digitalocean with new template
builder/virtualbox: use global config processing stuff
builder/virtualbox: stepHTTPServer uses previously setup listener
common: ProcessSingle to process a single template element
common: Process skips pre-processed keys
builder/virtualbox: pre-process vm_name so we can use that as builder
var