lang: Initial implementation of the mgmt language

This is an initial implementation of the mgmt language. It is a
declarative (immutable) functional, reactive, domain specific
programming language. It is intended to be a language that is:

* safe
* powerful
* easy to reason about

With these properties, we hope this language, and the mgmt engine will
allow you to model the real-time systems that you'd like to automate.

This also includes a number of other associated changes. Sorry for the
large size of this patch.

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,5 +1,8 @@
 ## Tips:
 
+* please read the style guide before submitting your patch:
+[docs/style-guide.md](docs/style-guide.md)
+
 * commit message titles must be in the form:
 ```topic: Capitalized message with no trailing period```
 or:

.github/settings.yml

@@ -10,10 +10,10 @@ repository:
   description: Next generation distributed, event-driven, parallel config management!
 
   # A URL with more information about the repository
-  homepage: https://ttboj.wordpress.com/?s=mgmtconfig
+  homepage: https://purpleidea.com/tags/mgmtconfig/
 
   # A comma-separated list of topics to set on the repository
-  topics: golang, go, configuration-management, config-management, devops, etcd, distributed-systems, graph-theory
+  topics: golang, go, configuration-management, config-management, devops, etcd, distributed-systems, graph-theory, choreography
 
   # Either `true` to make the repository private, or `false` to make it public.
   private: false