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.

examples/lang/printf1.mcl

@@ -0,0 +1,8 @@
+test "printf-a" {
+	anotherstr => printf("the %s is: %d", "answer", 42),
+}
+
+$format = "a %s is: %f"
+test "printf-b" {
+	anotherstr => printf($format, "cool number", 3.14159),
+}