add Mustache dependency
transform scaffold raw php templates into mustache templates

* move common code into helper method
* make taxonomy template more consistent with cpt template
* rename --label to --singular
replace {{post_type}} with {{slug}}
use {{label}} instead of {{slug}}, where appropriate
pass whole post to get_permalink() and cache the result
Merge pull request #268 from Automattic/proper-file-version

Require the file based on when the file was actually committed to core.
remove @maintainer and @subpackage tags
Merge pull request #265 from wp-cli/scaffold-mustache

Use Mustache for scaffold templates
first pass at `wp scaffold plugin`
use create_file() for cpt and tax scaffolds
add man page for `wp scaffold plugin`
always use the plugin slug for the textdomain
update top-level command descriptions and move add_command() below the class definitions
remove @subpackage commands/internals
replace --syn-list with --cmd-dump
add external syn-list.php utility
synopsis should always be a string
it's actually easier if we pass the whole 'wp' command
move read_json() to separate file
add cmd-list.php utility