Allow disalbing component generation.


**Above template with component generation enabled:**

```javascript
import { compileSpec } from 'htmlbars-compiler/compile';

var t = "<x-foo>Howdy {{name}}</x-foo>";
var spec = compileSpec(t);

/*  output below */

(function() {
  var child0 = (function() {
    function build(dom) {
      var el0 = dom.createDocumentFragment();
      var el1 = dom.createTextNode("Howdy ");
      dom.appendChild(el0, el1);
      var el1 = dom.createTextNode("");
      dom.appendChild(el0, el1);
      return el0;
    }
    var cachedFragment;
    return function template(context, env, contextualElement) {
      var dom = env.dom, hooks = env.hooks, get = env.get;
      dom.detectNamespace(contextualElement);
      if (cachedFragment === undefined) {
        cachedFragment = build(dom);
      }
      var fragment = dom.cloneNode(cachedFragment, true);
      dom.repairClonedNode(fragment,[1]);
      var morph0 = dom.createMorphAt(fragment,0,1,contextualElement);
      hooks.content(morph0, "name", context, [], {}, {type:"id",morph:morph0}, env);
      return fragment;
    };
  }())
  function build(dom) {
    var el0 = dom.createDocumentFragment();
    var el1 = dom.createTextNode("");
    dom.appendChild(el0, el1);
    var el1 = dom.createTextNode("");
    dom.appendChild(el0, el1);
    return el0;
  }
  var cachedFragment;
  return function template(context, env, contextualElement) {
    var dom = env.dom, hooks = env.hooks, get = env.get;
    dom.detectNamespace(contextualElement);
    if (cachedFragment === undefined) {
      cachedFragment = build(dom);
    }
    var fragment = dom.cloneNode(cachedFragment, true);
    dom.repairClonedNode(fragment,[0,1]);
    var morph0 = dom.createUnsafeMorphAt(fragment,0,1,contextualElement);
    hooks.component(morph0, "x-foo", context, {}, {type:"id",paramTypes:[],hashTypes:{},render:child0,morph:morph0}, env);
    return fragment;
  };
}())
```

**Above template with component generation disabled:**

```javascript
import { compileSpec } from 'htmlbars-compiler/compile';

var t = "<x-foo>Howdy {{name}}</x-foo>";
var spec = compileSpec(t, { disalbeComponentGeneration: true });

/*  output below */

(function() {
  function build(dom) {
    var el0 = dom.createElement("x-foo");
    var el1 = dom.createTextNode("Howdy ");
    dom.appendChild(el0, el1);
    return el0;
  }
  var cachedFragment;
  return function template(context, env, contextualElement) {
    var dom = env.dom, hooks = env.hooks, get = env.get;
    dom.detectNamespace(contextualElement);
    if (cachedFragment === undefined) {
      cachedFragment = build(dom);
    }
    var fragment = dom.cloneNode(cachedFragment, true);
    var morph0 = dom.createMorphAt(fragment,0,-1);
    hooks.content(morph0, "name", context, [], {}, {type:"id",morph:morph0}, env);
    return fragment;
  };
}())
```