Add support for POST services to use req.body and JSON-Schema.

This gets rid of the need to use URL parameters for POST service calls.  All of the dispatch function parameters can be sent in a POST body.  For example:

![poster-inventory-adjustment](https://f.cloud.github.com/assets/571574/1485641/e76ef0e8-4717-11e3-89da-ea08885eb7df.png)

This will change the Discovery Document to generate a service like this:

```javascript
...
  "services": {
    "Inventory": {
      "methods": {
        "adjustment": {
          "id": "Inventory.adjustment",
          "path": "inventory/adjustment",
          "httpMethod": "POST",
          "scopes": [
            "https://example.com/your-db-name-here/auth",
            "https://example.com/your-db-name-here/inventory"
          ],
          "description": "Perform Inventory Adjustments.",
          "request": {
            "$ref": "InventoryAdjustment"
          },
          "parameterOrder": [
            "itemSite",
            "quantity",
            "options"
          ]
        },
        ...
      }
    }
  }
```

The JSON-Schema section of the Discovery Doc will now have:
```javascript
...
    "InventoryAdjustment": {
      "properties": {
        "itemSite": {
          "title": "Item Site",
          "description": "UUID of itemSite",
          "type": "string",
          "$ref": "ItemSite/uuid"
        },
        "quantity": {
          "title": "Quantity",
          "description": "Quantity",
          "type": "number"
        },
        "options": {
          "title": "Options",
          "type": "object",
          "$ref": "InventoryAdjustmentOptions"
        }
      }
    },
    "InventoryAdjustmentOptions": {
      "properties": {
        "detail": {
          "title": "Detail",
          "description": "Distribution Detail",
          "type": "object",
          "items": {
            "$ref": "InventoryAdjustmentOptionsDetails"
          }
        },
        "asOf": {
          "title": "As Of",
          "description": "Transaction Timestamp, default to now()",
          "type": "string",
          "format": "date-time"
        },
        "docNumber": {
          "title": "Document Number",
          "description": "Document Number",
          "type": "string"
        },
        "notes": {
          "title": "Notes",
          "description": "Notes",
          "type": "string"
        },
        "value": {
          "title": "Value",
          "description": "Value",
          "type": "string"
        }
      }
    },
    "InventoryAdjustmentOptionsDetails": {
      "properties": {
        "quantity": {
          "title": "Quantity",
          "description": "Quantity",
          "type": "number"
        },
        "location": {
          "title": "Location",
          "description": "UUID of location",
          "type": "string"
        },
        "trace": {
          "title": "Trace",
          "description": "Trace (Lot or Serial) Number",
          "type": "string"
        },
        "expiration": {
          "title": "Expiration",
          "description": "Perishable expiration date",
          "type": "string",
          "format": "date"
        },
        "warranty": {
          "title": "Warranty",
          "description": "Warranty expire date",
          "type": "string",
          "format": "date"
        }
      }
    }
```